CVE-2021-29988

HighCVSS 8.8/10Last modified Jun 17, 2026

Description

Firefox incorrectly treated an inline list-item element as a block element, resulting in an out of bounds read or memory corruption, and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.

Metrics

CVSS 3.1 8.8/10CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-125 CWE-787

Affected software

Vendor	Product	Versions
Mozilla	Thunderbird	>= unspecified, < 78.13; >= unspecified, < 91
Mozilla	Firefox ESR	>= unspecified, < 78.13
Mozilla	Firefox	>= unspecified, < 91

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1717922Exploit, Issue Tracking, Vendor Advisory
https://security.gentoo.org/glsa/202202-03Third Party Advisory
https://security.gentoo.org/glsa/202208-14Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2021-33/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-34/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-35/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-36/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1717922Exploit, Issue Tracking, Vendor Advisory
https://security.gentoo.org/glsa/202202-03Third Party Advisory
https://security.gentoo.org/glsa/202208-14Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2021-33/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-34/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-35/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-36/Vendor Advisory

Timeline

Published: Aug 17, 2021
Last modified: Jun 17, 2026
NVD status: Modified

Related CVEs from 2021

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