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CVE-2023-6858
Firefox was susceptible to a heap buffer overflow in `nsTextFragment` due to insufficient OOM handling. This vulnerability affects Firefox…
High8.8EPSS 1.5%
- Published
- Updated
- Reserved
- Assigned by
- mozilla
Description
Firefox was susceptible to a heap buffer overflow in `nsTextFragment` due to insufficient OOM handling. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.
Timeline
ID reserved
By mozilla
- 4 days later
· 4 days later
Published
- 17 months later
· 17 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)
- 1.5% · top 25% of all CVEs (7 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.
Weakness
- Heap buffer overflow in nsTextFragment
- CWE-787 Out-of-bounds Write (opens in a new tab)All about CWE-787 and its CVEs
Affected products
- affected unspecified – < 115.6
- affected unspecified – < 115.6
- affected unspecified – < 121
References (9)
- https://bugzilla.mozilla.org/show_bug.cgi?id=1826791 (opens in a new tab)x_transferred
- https://www.mozilla.org/security/advisories/mfsa2023-54/ (opens in a new tab)x_transferred
- https://www.mozilla.org/security/advisories/mfsa2023-55/ (opens in a new tab)x_transferred
- https://www.mozilla.org/security/advisories/mfsa2023-56/ (opens in a new tab)x_transferred
- https://www.debian.org/security/2023/dsa-5581 (opens in a new tab)x_transferred
- https://www.debian.org/security/2023/dsa-5582 (opens in a new tab)x_transferred
- https://lists.debian.org/debian-lts-announce/2023/12/msg00020.html (opens in a new tab)x_transferred
- https://lists.debian.org/debian-lts-announce/2023/12/msg00021.html (opens in a new tab)x_transferred
- https://security.gentoo.org/glsa/202401-10 (opens in a new tab)x_transferred
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)
- 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://trackcve.app/cve/CVE-2023-6858)Record last updated .