Cyber Resilience

CVE-2022-26387

HighPublic PoC

Published: 22 December 2022

Published
22 December 2022
Modified
15 April 2025
KEV Added
—
Patch
—
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0024 46.8th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2022-26387 is a high-severity Time-of-check Time-of-use (TOCTOU) Race Condition (CWE-367) vulnerability in Mozilla Firefox. Its CVSS base score is 7.5 (High).

Operationally, ranked at the 46.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

When installing an add-on, Firefox verified the signature before prompting the user; but while the user was confirming the prompt, the underlying add-on file could have been modified and Firefox would not have noticed. This vulnerability affects Firefox < 98,…

more

Firefox ESR < 91.7, and Thunderbird < 91.7.

CWE(s)
CWE-367

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

mozilla
firefox
≤ 98.0
mozilla
firefox esr
≤ 91.7
mozilla
thunderbird
≤ 91.7

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

AU-8 Time Stamps
addresses: CWE-367

Timestamps meeting UTC or offset standards help identify TOCTOU issues through precise chronological reconstruction of check/use operations.

References