Vulnerability · Published Oct 13, 2026 · Assigned by mozilla

CVE-2026-109769Information disclosure in the Networking: Cache component

Medium 4.3

In plain English

A medium-severity information exposure in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).

Severity (CVSS 3.1)4.3Medium
Exploit odds (30 days)0.2%top 89.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Information disclosure in the Networking: Cache component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Ubuntu:22.04:LTSmozjs102no fix listedUBUNTU-CVE-2026-109769
Ubuntu:24.04:LTSmozjs102no fix listedUBUNTU-CVE-2026-109769
Ubuntu:24.04:LTSmozjs115no fix listedUBUNTU-CVE-2026-109769
Ubuntu:22.04:LTSmozjs78no fix listedUBUNTU-CVE-2026-109769
Ubuntu:22.04:LTSmozjs91no fix listedUBUNTU-CVE-2026-109769
Ubuntu:22.04:LTSthunderbirdno fix listedUBUNTU-CVE-2026-109769

Affected products (as reported)

VendorProductVersions
Mozilla Firefox see references
Mozilla Thunderbird see references

Weakness: CWE-200 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

References