Track vulnerabilities like this one.
Sign up free to get alerted when software you use is affected.
10.0
CVE-2025-68121: Go TLS may resume connections with wrong certificates
CVE-2025-68121 · published 7 months ago
Summary
The TLS component in the Go programming language can mistakenly reuse a previous secure session if the list of trusted certificates is changed between the first and later connections. This could let a client or server accept a connection it should have rejected, potentially exposing data to the wrong party. To prevent this, avoid modifying the trusted‑certificate settings after a connection is established and apply the latest Go updates that address the issue.
What to do
- Update stdlib to version 1.26.0-rc.3.
- Update debian golang-1.25 to version 1.25.6-1.
- Update debian rootio-golang-1.24 to version 1.24.4-1.root.io.20.
- Update debian rootio-golang-1.24 to version 1.24.4-1.root.io.19.
- Update debian golang-1.24 to version 1.24.4-1.root.io.20.
- Update golang to version 1.25.7.
Affected software
| Ecosystem | Vendor | Product | Affected versions |
|---|---|---|---|
| – | golang | go |
< 1.24.13 >= 1.25.0, < 1.25.7 1.26.0 cpe:2.3:a:golang:go:*:*:*:*:*:*:*:* |
| Go | – | stdlib |
>= 1.26.0-rc.1, < 1.26.0-rc.3 Fix: upgrade to 1.26.0-rc.3
|
| Debian:11 | debian | golang-1.15 | All versions |
| Debian:12 | debian | golang-1.19 | All versions |
| Debian:13 | debian | golang-1.24 | All versions |
| Debian:14 | debian | golang-1.25 |
< 1.25.6-1 Fix: upgrade to 1.25.6-1
|
| Ubuntu:Pro:16.04:LTS | canonical | golang-1.18 | All versions |
| Ubuntu:Pro:18.04:LTS | canonical | golang-1.16 | All versions |
| Ubuntu:Pro:18.04:LTS | canonical | golang-1.18 | All versions |
| Ubuntu:Pro:20.04:LTS | canonical | golang-1.16 | All versions |
| Ubuntu:20.04:LTS | canonical | golang-1.18 | All versions |
| Ubuntu:20.04:LTS | canonical | golang-1.20 | All versions |
| Ubuntu:20.04:LTS | canonical | golang-1.21 | All versions |
| Ubuntu:20.04:LTS | canonical | golang-1.22 | All versions |
| Ubuntu:22.04:LTS | canonical | golang-1.17 | All versions |
| Ubuntu:22.04:LTS | canonical | golang-1.18 | All versions |
| Ubuntu:22.04:LTS | canonical | golang-1.20 | All versions |
| Ubuntu:22.04:LTS | canonical | golang-1.21 | All versions |
| Ubuntu:22.04:LTS | canonical | golang-1.22 | All versions |
| Ubuntu:22.04:LTS | canonical | golang-1.23 | All versions |
| Ubuntu:22.04:LTS | canonical | golang-1.24 | All versions |
| Ubuntu:24.04:LTS | canonical | golang-1.21 | All versions |
| Ubuntu:24.04:LTS | canonical | golang-1.22 | All versions |
| Ubuntu:24.04:LTS | canonical | golang-1.23 | All versions |
| Ubuntu:24.04:LTS | canonical | golang-1.24 | All versions |
| Root:Debian:13 | debian | rootio-golang-1.24 |
< 1.24.4-1.root.io.20 < 1.24.4-1.root.io.19 Fix: upgrade to 1.24.4-1.root.io.20
|
| Ubuntu:25.10 | canonical | golang-1.23 | All versions |
| Ubuntu:25.10 | canonical | golang-1.24 | All versions |
| Ubuntu:25.10 | canonical | golang-1.25 | All versions |
| Ubuntu:26.04 | canonical | golang-1.23 | All versions |
| Ubuntu:26.04 | canonical | golang-1.24 | All versions |
| Ubuntu:26.04 | canonical | golang-1.25 | All versions |
| Root:Debian:13 | debian | golang-1.24 |
< 1.24.4-1.root.io.20 Fix: upgrade to 1.24.4-1.root.io.20
|
| Bitnami | – | golang |
>= 1.25.0-0, < 1.25.7 Fix: upgrade to 1.25.7
|
Original advisory text
Unexpected session resumption in crypto/tls
During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between the initial handshake and the resumed handshake, the resumed handshake may succeed when it should have failed. This may happen when a user calls Config.Clone and mutates the returned Config, or uses Config.GetConfigForClient. This can cause a client to resume a session with a server that it would not have resumed with during the initial handshake, or cause a server to resume a session with a client that it would not have resumed with during the initial handshake.
References
- https://security-tracker.debian.org/tracker/CVE-2025-68121 Vendor Advisory
- https://ubuntu.com/security/CVE-2025-68121 Third Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2025-68121 Third Party Advisory
- https://groups.google.com/g/golang-announce/c/Vd2tYVM8eUc Third Party Advisory
- https://github.com/golang/go/issues/77113 Third Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2025-68121 URL
- https://pkg.go.dev URL
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68121... Vendor Advisory
- https://go.dev/issue/77217 Third Party Advisory
- https://groups.google.com/g/golang-announce/c/K09ubi9FQFk URL
- https://pkg.go.dev/vuln/GO-2026-4337 Vendor Advisory
- https://go.dev/cl/737700 Patch
Severity
10.0
Critical
CVSS 3.1: 10.0 (NVD)
CVSS 3.1: 9.1 (OSV)
Exploitation
EPSS <1%
Type
CWE-295Improper Certificate Validation
Timeline
Published5 Feb 2026
Updated25 Sep 2026
First seen6 Mar 2026
Sources
CVE-2025-68121 · NVD
GO-2026-4337 · OSV
CVE-2025-68121 · OSV
DEBIAN-CVE-2025-68121 · OSV
UBUNTU-CVE-2025-68121 · OSV
BIT-golang-2025-68121 · OSV
Track software like this
Free during beta