🛡️ CVE-2025-1012 on Ubuntu — firefox

Distribution advisory

This page covers CVE-2025-1012 as tracked by Ubuntu, for the package firefox. The fix is available in version 135.0+build2-0ubuntu0.20.04.1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

• Attack vector: Network — reachable from anywhere that can route to the service.
• Attack complexity: High — the attacker first has to win a race, learn a secret or otherwise prepare the target.
• Privileges required: None — an unauthenticated stranger can try it.
• User interaction: Required — someone has to click, open or visit something.
• Scope: Unchanged — the damage stays inside the vulnerable component.
• Confidentiality impact: High — total loss, or loss the attacker controls.
• Integrity impact: High — total loss, or loss the attacker controls.
• Availability impact: High — total loss, or loss the attacker controls.

Weakness class

UBUNTU-CVE-2025-1012 is classified as CWE-416: Use After Free. Memory is used after being released, so its contents may already belong to something else.

Affected software

UBUNTU-CVE-2025-1012 is recorded against 9 packages.

• firefox (fixed in 135.0+build2-0ubuntu0.20.04.1)
• mozjs102
• mozjs115
• mozjs38
• mozjs52
• mozjs68
• mozjs78
• mozjs91
• thunderbird (fixed in 1:128.12.0+build1-0ubuntu0.22.04.1)

Timeline and source

Published on 6 February 2025 and last revised on 29 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

ubuntu.com (Report)
www.cve.org (Report)
www.mozilla.org (Report)
www.mozilla.org (Report)
www.mozilla.org (Report)
bugzilla.mozilla.org (Report)
www.mozilla.org (Report)
www.mozilla.org (Report)
www.mozilla.org (Report)
www.mozilla.org (Report)
www.mozilla.org (Report)
ubuntu.com (Advisory)
ubuntu.com (Advisory)

Other advisories for this package

firefox has other advisories on record. If you are patching this one, these are worth checking on the same host:

• RHSA-2026:47104 (published 4 Aug 2026)
• RLSA-2026:47104 (published 3 Aug 2026)
• RLSA-2026:47101 (published 30 Jul 2026)
• RHSA-2026:47101 (published 29 Jul 2026)
• RLSA-2026:47105 (published 29 Jul 2026)
• RHSA-2026:47105 (published 29 Jul 2026)
• CGA-6g6w-pw53-638x (published 16 Jul 2026)
• RHSA-2026:39011 (published 14 Jul 2026)

Same weakness in other software

These advisories are the same class of weakness (CWE-416: Use After Free) in other software:

• CVE-2022-21540 (5.3 Medium, published 8 May 2026)
• CVE-2022-50552 (7.8 High, published 7 Oct 2025)
• CVE-2022-50542 (7.8 High, published 7 Oct 2025)
• CVE-2022-50496 (7.8 High, published 4 Oct 2025)
• CVE-2022-50492 (7.8 High, published 4 Oct 2025)
• CVE-2022-50488 (7.8 High, published 4 Oct 2025)
• CVE-2022-50507 (7.8 High, published 4 Oct 2025)
• CVE-2022-50423 (7.8 High, published 1 Oct 2025)

CVE-2025-1012 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Affected Packages

References