CVE-2021-43539
Status: ModifiedHigh (8.8)—
Failure to correctly record the location of live pointers across wasm instance calls resulted in a GC occurring within the call not tracing those live pointers. This could have led to a use-after-free causing a potentially exploitable crash. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Base score: 8.8
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 1.73%
- Percentile among all scored CVEs: 77
- Score date: 10/7/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (4)
CWEs
- CWE-416
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1739683
- https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html
- https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html
- https://security.gentoo.org/glsa/202202-03
- https://security.gentoo.org/glsa/202208-14
- https://www.debian.org/security/2021/dsa-5026
- https://www.debian.org/security/2022/dsa-5034
- https://www.mozilla.org/security/advisories/mfsa2021-52/
- https://www.mozilla.org/security/advisories/mfsa2021-53/
- https://www.mozilla.org/security/advisories/mfsa2021-54/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1739683
- https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html
- https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html
- https://security.gentoo.org/glsa/202202-03
- https://security.gentoo.org/glsa/202208-14
- https://www.debian.org/security/2021/dsa-5026
- https://www.debian.org/security/2022/dsa-5034
- https://www.mozilla.org/security/advisories/mfsa2021-52/
- https://www.mozilla.org/security/advisories/mfsa2021-53/
- https://www.mozilla.org/security/advisories/mfsa2021-54/
Raw JSON (NVD)
Show
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}
],
"lastModified": "2026-06-17T04:11:05.720",
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