CVE-2025-1017
criticalMemory safety bugs present in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6.
Vendor / product: Mozilla — firefox
Memory safety bugs present in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6. 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 was fixed in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.
CVSS
9.8
9.8 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2025-02-04 14:15
Modified: 2026-10-05 15:10
NVD status: Modified
Last synced 2 days ago
Verified against the source API 2026-10-27 07:06 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
mozilla / firefox <128.7.0, <135.0
mozilla / thunderbird ≥128.0.1 <128.7.0, ≥131.0 <135.0
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2025-07/
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2025-09/
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2025-10/
Vendor advisory: https://www.mozilla.org/security/advisories/mfsa2025-11/
References
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1926256%2C1935984%2C1935471 security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2025-07/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2025-09/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2025-10/ security@mozilla.org
- https://www.mozilla.org/security/advisories/mfsa2025-11/ security@mozilla.org
- https://lists.debian.org/debian-lts-announce/2025/02/msg00006.html af854a3a-2127-422b-91ae-364da2661108
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 07:06 UTC · record ↗