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Thunderbird: Malicious Email Can Steal Secret Info
OESA-2026-1539
Summary
Thunderbird users are at risk if they open certain HTML emails with embedded encrypted messages. If the email is crafted to use CSS styles to extract the encrypted contents, the secret info could be revealed. Update to the latest version of Thunderbird to fix this issue.
What to do
- Update thunderbird to version 140.8.0-1.oe2403sp2.
Affected software
| Vendor | Product | Affected versions | Fix available |
|---|---|---|---|
| – | thunderbird | <= 140.8.0-1.oe2403sp2 | 140.8.0-1.oe2403sp2 |
Original title
thunderbird security update
Original description
Mozilla Thunderbird is a standalone mail and newsgroup client.
Security Fix(es):
When a user explicitly requested Thunderbird to decrypt an inline OpenPGP message that was embedded in a text section of an email that was formatted and styled with HTML and CSS, then the decrypted contents were rendered in a context in which the CSS styles from the outer messages were active. If the user had additionally allowed loading of the remote content referenced by the outer email message, and the email was crafted by the sender using a combination of CSS rules and fonts and animations, then it was possible to extract the secret contents of the email. This vulnerability affects Thunderbird < 147.0.1 and Thunderbird < 140.7.1.(CVE-2026-0818)
Heap buffer overflow in libvpx. This vulnerability affects Firefox < 147.0.4, Firefox ESR < 140.7.1, Firefox ESR < 115.32.1, Thunderbird < 140.7.2, and Thunderbird < 147.0.2.(CVE-2026-2447)
Incorrect boundary conditions in the WebRTC: Audio/Video component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2757)
Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2758)
Incorrect boundary conditions in the Graphics: ImageLib component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2759)
Sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2760)
Sandbox escape in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2761)
Integer overflow in the JavaScript: Standard Library component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2762)
Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2763)
JIT miscompilation, use-after-free in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2764)
Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2765)
Use-after-free in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2766)
Use-after-free in the JavaScript: WebAssembly component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2767)
Sandbox escape in the Storage: IndexedDB component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2768)
Use-after-free in the Storage: IndexedDB component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2769)
Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2770)
Undefined behavior in the DOM: Core & HTML component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2771)
Use-after-free in the Audio/Video: Playback component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2772)
Incorrect boundary conditions in the Web Audio component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2773)
Integer overflow in the Audio/Video component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2774)
Mitigation bypass in the DOM: HTML Parser component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2775)
Privilege escalation in the Messaging System component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2777)
Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2778)
Incorrect boundary conditions in the Networking: JAR component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2779)
Integer overflow in the Libraries component in NSS. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2781)
Privilege escalation in the Netmonitor component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2782)
Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2783)
Mitigation bypass in the DOM: Security component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2784)
Invalid pointer in the JavaScript Engine component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2785)
Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2786)
Use-after-free in the DOM: Window and Location component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2787)
Incorrect boundary conditions in the Audio/Video: GMP component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2788)
Use-after-free in the Graphics: ImageLib component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2789)
Same-origin policy bypass in the Networking: JAR component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2790)
Mitigation bypass in the Networking: Cache component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2791)
Memory safety bugs present in Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2792)
Memory safety bugs present in Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2793)
Security Fix(es):
When a user explicitly requested Thunderbird to decrypt an inline OpenPGP message that was embedded in a text section of an email that was formatted and styled with HTML and CSS, then the decrypted contents were rendered in a context in which the CSS styles from the outer messages were active. If the user had additionally allowed loading of the remote content referenced by the outer email message, and the email was crafted by the sender using a combination of CSS rules and fonts and animations, then it was possible to extract the secret contents of the email. This vulnerability affects Thunderbird < 147.0.1 and Thunderbird < 140.7.1.(CVE-2026-0818)
Heap buffer overflow in libvpx. This vulnerability affects Firefox < 147.0.4, Firefox ESR < 140.7.1, Firefox ESR < 115.32.1, Thunderbird < 140.7.2, and Thunderbird < 147.0.2.(CVE-2026-2447)
Incorrect boundary conditions in the WebRTC: Audio/Video component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2757)
Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2758)
Incorrect boundary conditions in the Graphics: ImageLib component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2759)
Sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2760)
Sandbox escape in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2761)
Integer overflow in the JavaScript: Standard Library component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2762)
Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2763)
JIT miscompilation, use-after-free in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2764)
Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2765)
Use-after-free in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2766)
Use-after-free in the JavaScript: WebAssembly component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2767)
Sandbox escape in the Storage: IndexedDB component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2768)
Use-after-free in the Storage: IndexedDB component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2769)
Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2770)
Undefined behavior in the DOM: Core & HTML component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2771)
Use-after-free in the Audio/Video: Playback component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2772)
Incorrect boundary conditions in the Web Audio component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2773)
Integer overflow in the Audio/Video component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2774)
Mitigation bypass in the DOM: HTML Parser component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2775)
Privilege escalation in the Messaging System component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2777)
Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2778)
Incorrect boundary conditions in the Networking: JAR component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2779)
Integer overflow in the Libraries component in NSS. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2781)
Privilege escalation in the Netmonitor component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2782)
Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2783)
Mitigation bypass in the DOM: Security component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2784)
Invalid pointer in the JavaScript Engine component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2785)
Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2786)
Use-after-free in the DOM: Window and Location component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2787)
Incorrect boundary conditions in the Audio/Video: GMP component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2788)
Use-after-free in the Graphics: ImageLib component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2789)
Same-origin policy bypass in the Networking: JAR component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2790)
Mitigation bypass in the Networking: Cache component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2791)
Memory safety bugs present in Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2792)
Memory safety bugs present in Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.(CVE-2026-2793)
- https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA... Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-0818 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2447 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2757 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2758 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2759 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2760 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2761 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2762 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2763 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2764 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2765 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2766 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2767 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2768 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2769 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2770 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2771 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2772 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2773 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2774 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2775 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2777 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2778 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2779 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2781 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2782 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2783 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2784 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2785 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2786 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2787 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2788 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2789 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2790 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2791 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2792 Vendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-2793 Vendor Advisory
Published: 6 Mar 2026 · Updated: 6 Mar 2026 · First seen: 6 Mar 2026