CVE-2026-5260

Publication date 30 April 2026

Last updated 6 July 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

8.2 · High

Score breakdown

Description

A flaw was found in libgnutls. A remote attacker, by sending an extremely short premaster secret during an RSA key exchange to a server using an RSA key backed by a PKCS#11 token, could trigger a short heap overread. This memory corruption vulnerability could lead to information disclosure.

Read the notes from the security team

Status

Package Ubuntu Release Status
gnutls28 26.10 stonking
Not affected
26.04 LTS resolute
Fixed in 3.8.12-2ubuntu1.1
25.10 questing
Fixed in 3.8.9-3ubuntu2.2
24.04 LTS noble
Fixed in 3.8.3-1.1ubuntu3.6
22.04 LTS jammy
Fixed in 3.7.3-4ubuntu1.9
20.04 LTS focal
Fixed in 3.6.13-2ubuntu1.12+esm2
18.04 LTS bionic
Fixed in 3.5.18-1ubuntu1.6+esm3
16.04 LTS xenial
Not affected

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Notes

mrmajumder

xenial is not-affected: gnutls 3.4.10 uses the allocating decrypt API gnutls_privkey_decrypt_data() in both lib/auth/rsa.c and lib/auth/rsa_psk.c, where the callee (PKCS#11) allocates the plaintext to its real size, so the short heap overread cannot occur.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
gnutls28

Severity score breakdown

CVSS version: CVSS v3.0

Base score 8.2 · High

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

References

Related Ubuntu Security Notices (USN)

Other references

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