CVE detail

CVE-2021-23991 — CVE-2021-23991

Published 2021-06-24 · Modified 2026-06-17 · Vendor mozilla · Product thunderbird · Source nvd

MEDIUM

severity

CVSS-derived band

6.8

CVSS v3

0–10 scale

0.0103

EPSS probability

exploitation probability, 30d

61.0%

EPSS percentile

percentile vs all CVEs

NOT LISTED

CISA KEV

known exploited catalog

Description

If a Thunderbird user has previously imported Alice's OpenPGP key, and Alice has extended the validity period of her key, but Alice's updated key has not yet been imported, an attacker may send an email containing a crafted version of Alice's key with an invalid subkey, Thunderbird might subsequently attempt to use the invalid subkey, and will fail to send encrypted email to Alice. This vulnerability affects Thunderbird < 78.9.1.

Remediation

No vendor-published fix data in our corpus for this CVE. Check the references below or the vendor's PSIRT / security advisories page.

References

cvedb.io · NVD · CISA KEV · FIRST EPSS · vendor advisories (CVE Program List v5). Informational only, no warranty — verify every remediation against the vendor advisory before acting on it. This product uses data from the NVD API but is not endorsed or certified by the NVD, CISA, FIRST.org or any vendor named. CVE® is a registered trademark of The MITRE Corporation.