CVE-2021-23975

6.5 mediumEPSS 1.0%

Medium (6.5) in mozilla firefox. EPSS 1.0% chance of exploitation in the next 30 days.

The developer page about:memory has a Measure function for exploring what object types the browser has allocated and their sizes. When this function was invoked we incorrectly called the sizeof function, instead of using the API method that checks for invalid pointers. This vulnerability affects Firefox < 86.

Severity

CVSS 3.1

6.5 medium

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS: 1.0% chance of exploitation in the next 30 days; higher than 63% of CVEs (scores of 2026-10-31)
CWE: CWE-862
Published: 2021-02-26
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

mozilla:firefox

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1685145
https://security.gentoo.org/glsa/202104-10
https://www.mozilla.org/security/advisories/mfsa2021-07/
https://bugzilla.mozilla.org/show_bug.cgi?id=1685145
https://security.gentoo.org/glsa/202104-10

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