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CVE-2025-1012
Use-after-free during concurrent delazification
Critical9.8EPSS 0.45%
- Published
- Updated
- Reserved
- Assigned by
- mozilla
Description
A race during concurrent delazification could have led to a use-after-free. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.
Timeline
ID reserved
By mozilla
Published
- 14 months later
· 14 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.45% · top 60% of all CVEs (9 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Weakness
Affected products
- unaffected 115.20 – ≤ 115.*
- unaffected 128.7 – ≤ 128.*
- unaffected 135 – ≤ *
- unaffected 128.7 – ≤ 128.*
- unaffected 135 – ≤ *
References (8)
- https://bugzilla.mozilla.org/show_bug.cgi?id=1939710 (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-07/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-08/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-09/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-10/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-11/ (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/02/msg00006.html (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/02/msg00005.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-1967 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-1012)Record last updated .