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CVE-2025-8027JavaScript engine only wrote partial return value to stack
- 6.5MediumCVSS base score
- 0.43%Exploitation in 30 daysEPSS · top 62% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
Timeline
ID reserved
By mozilla
Published
- 9 months later
· 9 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 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| NVDNVD · Modified | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.43% · top 62% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Affected products
- unaffected 115.26 – ≤ 115.*
- unaffected 128.13 – ≤ 128.*
- unaffected 140.1 – ≤ 140.*
- unaffected 141 – ≤ *
- unaffected 128.13 – ≤ 128.*
- unaffected 140.1 – ≤ 140.*
- unaffected 141 – ≤ *
References
References9
- https://bugzilla.mozilla.org/show_bug.cgi?id=1968423 (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-56/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-57/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-58/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-59/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-61/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-62/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2025-63/ (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/07/msg00016.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-2025-22372 (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-2025-8027)Record last updated .