Firefox · Memory Safety Bugs Fixed
Affects MicrosoftSource GCVE Database
Not known to be exploited · CVSS 7.5 High.
Data as of 14 Nov 2026, 09:48 UTC
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 21 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 13 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Security Response Center Microsoft | Affected
| Fixed in– |
AI-suggested
Since the description states that the bugs were fixed in Firefox 150 and Thunderbird 150, users should update to these versions to mitigate the issue. For the Microsoft product version 4.0 mentioned, no remediation guidance is available.
Description
Memory safety bugs affecting Firefox 150 and Thunderbird 150 have been identified and fixed. The advisory references Microsoft Security Response Center but provides no detailed technical information or CVSS score. No known exploits are reported in the wild. The affected version explicitly stated is version 4.0 of an unspecified Microsoft product, which appears inconsistent with the Firefox and Thunderbird mention.