CVE-2025-10533: Mozilla Firefox · Integer Overflow
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 8.8 High : upgrade to 143 soon.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 143
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade Mozilla Firefox to 143.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Firefox | Affected
| Fixed in
|
AI-suggested
Official fixes for this vulnerability are available in Firefox 143, Firefox ESR 115.28, Firefox ESR 140.3, Thunderbird 143, and Thunderbird 140.3. Users and administrators should update to these versions or later to remediate the vulnerability. Since the vendor advisory confirms the availability of patches, applying these updates is the recommended mitigation. No additional mitigation steps are indicated by the vendor.
Description
Integer overflow in the SVG component. This vulnerability was fixed in Firefox 143, Firefox ESR 115.28, Firefox ESR 140.3, Thunderbird 143, and Thunderbird 140.3.
References
- bugzilla.mozilla.org/show_bug.cgi?id=1980788 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-73/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-74/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-75/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-77/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-78/ (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/09/msg00026.html (opens in a new tab)