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VulnerabilityPublished Updated

CVE-2025-1933: Mozilla Firefox

Affects Mozilla FirefoxSource CVE Database V5

0

Not known to be exploited · CVSS 7.6 High : upgrade to 136 soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
7.6High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 136
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 4 Mar 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: 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 26 Oct 2026.

What to do

Upgrade Mozilla Firefox to 136.

Affected software

ProductAffectedFixed in
Mozilla FirefoxAffected
  • <136
Fixed in
  • 136

AI-suggested

Mozilla has released official fixes for this vulnerability in Firefox 136, Firefox ESR 115.21, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8. Users and administrators should update affected products to these versions or later to remediate the issue. Since the vulnerability is patched, no additional mitigation steps are required beyond applying the official updates.

Description

On 64-bit CPUs, when the JIT compiles WASM i32 return values they can pick up bits from left over memory. This can potentially cause them to be treated as a different type. This vulnerability was fixed in Firefox 136, Firefox ESR 115.21, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.

References

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