Track vulnerabilities like this one.
Sign up free to get alerted when software you use is affected.
8.2
osbuild-composer may let attackers gain higher privileges
published 1 month ago
Summary
The osbuild-composer tool that builds custom operating system images can be tricked into processing specially crafted web addresses, potentially allowing a user to gain elevated rights or run unwanted code. It can also expose information or cause service disruptions. Update to the latest version of osbuild-composer to apply the fixes and protect your systems.
What to do
- Update rocky osbuild-composer to version 0:165.1-5.el10_2.rocky.0.1.
Affected software
| Ecosystem | Vendor | Product | Affected versions |
|---|---|---|---|
| Rocky Linux:10 | rocky | osbuild-composer |
< 0:165.1-5.el10_2.rocky.0.1 Fix: upgrade to 0:165.1-5.el10_2.rocky.0.1
|
Original advisory text
Important: osbuild-composer security update
A service for building customized OS artifacts, such as VM images and OSTree commits, that uses osbuild under the hood. Besides building images for local usage, it can also upload images directly to cloud. It is compatible with composer-cli and cockpit-composer clients.
Security Fix(es):
* golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing (CVE-2026-39821)
* golang.org/x/net/html: golang: golang.org/x/net/html: Cross-Site Scripting via HTML parsing bypass (CVE-2026-27136)
* golang.org/x/net/html: golang.org/x/net/html: Arbitrary code execution via Cross-Site Scripting (CVE-2026-25681)
* golang.org/x/net/html: golang: golang.org/x/net/html: Cross-Site Scripting via unexpected HTML tree rendering (CVE-2026-42502)
* github.com/open-telemetry/opentelemetry-go: go.opentelemetry.io/otel/baggage: go.opentelemetry.io/otel/propagation: OpenTelemetry-Go: Denial of Service via oversized baggage headers (CVE-2026-41178)
* github.com/labstack/echo: Echo: Unauthorized Information Disclosure via URL Path Decoding Discrepancy (CVE-2026-55677)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Security Fix(es):
* golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing (CVE-2026-39821)
* golang.org/x/net/html: golang: golang.org/x/net/html: Cross-Site Scripting via HTML parsing bypass (CVE-2026-27136)
* golang.org/x/net/html: golang.org/x/net/html: Arbitrary code execution via Cross-Site Scripting (CVE-2026-25681)
* golang.org/x/net/html: golang: golang.org/x/net/html: Cross-Site Scripting via unexpected HTML tree rendering (CVE-2026-42502)
* github.com/open-telemetry/opentelemetry-go: go.opentelemetry.io/otel/baggage: go.opentelemetry.io/otel/propagation: OpenTelemetry-Go: Denial of Service via oversized baggage headers (CVE-2026-41178)
* github.com/labstack/echo: Echo: Unauthorized Information Disclosure via URL Path Decoding Discrepancy (CVE-2026-55677)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
References
- https://errata.rockylinux.org/RLSA-2026:66432 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2480756 Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2480757 Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2480761 Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2480762 Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2484830 Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2493622 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:66432 Vendor Advisory
Internet-facing
14 days
Internal
At next upgrade
- Not known to be exploited
- Needs hands-on effort to exploit (estimated)
- Gives an attacker full control (estimated)
Timeline
Published11 Sep 2026
Updated11 Sep 2026
First seen11 Sep 2026
Sources
RLSA-2026:66432 · OSV
Track software like this
Free during beta