CVE-2025-5265: Mozilla Firefox · Command Injection
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 4.8 Medium : upgrade to 139 when convenient.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 139
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 27 May 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 2026-10-25.
What to do
Upgrade Mozilla Firefox to 139.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Firefox | Affected
| Fixed in
|
AI-suggested
This vulnerability has been fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11. Users and administrators should update affected Firefox for Windows installations to these versions or later to remediate the issue. No additional mitigation steps are required once the update is applied.
Description
Due to insufficient escaping of the ampersand character in the “Copy as cURL” feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. *This bug only affects Firefox for Windows. Other versions of Firefox are unaffected.*. This vulnerability was fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
References
- bugzilla.mozilla.org/show_bug.cgi?id=1962301 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-42/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-43/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-44/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-45/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-46/ (opens in a new tab)