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CVE-2025-4919Out-of-bounds access when optimizing linear sums
- 8.8HighCVSS base score
- 9.1%Exploitation in 30 daysEPSS · top 4.6% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2.
Timeline
ID reserved
By mozilla
Published
- 11 months later
· 11 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 | High8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 9.1% · top 4.6% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.8.
Affected products
- unaffected 115.23.1 – ≤ 115.*
- unaffected 128.10.1 – ≤ 128.*
- unaffected 138.0.4 – ≤ *
- unaffected 128.10.2 – ≤ 128.*
- unaffected 138.0.2 – ≤ *
References
References8
- https://bugzilla.mozilla.org/show_bug.cgi?id=1966614 (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-36/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-37/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-38/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-40/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-41/ (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/05/msg00024.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-2025-15598 (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-2025-4919)Record last updated .