Skip to main content
CVE-2026-5731VulnerabilityPublished Updated

Red Hat Security Advisory: firefox security update

Affects Red Hat firefoxSource GCVE Database

0
Compare

Mentioned vulnerabilities

Authoritative record:CVE-2026-5731· Critical 9.8

Not known to be exploited · CVSS 9.8 Critical · fixed in Red Hat package updates : patch Red Hat firefox as a priority.

Data as of 30 Oct 2026, 21:35 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 140.9.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 7 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 30 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Red Hat Product Security Red HatAffected
  • =115.34.0
  • =140.9.0
  • =149.0.1
Fixed in–

AI-suggested

Security fixes have been released in Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2, and Thunderbird 149.0.2. Users and administrators should update to these versions to remediate the vulnerabilities. No additional mitigation steps are indicated in the advisory.

Description

Multiple security vulnerabilities affecting Mozilla Firefox and Thunderbird have been addressed in recent updates. These include arbitrary code execution due to a use-after-free in libpng, information disclosure and denial of service via out-of-bounds read/write in libpng's Neon palette expansion, and several memory safety bugs and integer overflow issues in Firefox and Thunderbird components.

References

Community reviews

Loading reviews…