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Fencer Vulns
high 7.5

CVE-2021-29950 json

Thunderbird unprotects a secret OpenPGP key prior to using it for a decryption, signing or key import task.

published 2021-06-24 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-16409

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

Thunderbird unprotects a secret OpenPGP key prior to using it for a decryption, signing or key import task. If the task runs into a failure, the secret key may remain in memory in its unprotected state. This vulnerability affects Thunderbird < 78.8.1.

Patch / fix

  • Mozilla Thunderbird 78.8.1
  • thunderbird Debian 14, Debian 13, Debian 12 1:78.9.0-1

debian advisories DEBIAN-CVE-2021-29950

  • thunderbird Ubuntu 18.04 LTS 1:78.8.1+build1-0ubuntu0.18.04.1
  • thunderbird Ubuntu 20.04 LTS 1:78.8.1+build1-0ubuntu0.20.04.1

ubuntu advisories UBUNTU-CVE-2021-29950

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • thunderbird RHEL 8 78.9.1-1.el8_3
  • thunderbird RHEL 7 78.9.1-1.el7_9
  • thunderbird RHEL 8.2 EUS 78.9.1-1.el8_2
  • thunderbird RHEL 8.1 EUS 78.9.1-1.el8_1

red hat advisories RHSA-2021:1201RHSA-2021:1193RHSA-2021:1192RHSA-2021:1190

  • MozillaThunderbird SLE Workstation Extension 15 SP3, SLE Workstation Extension 15 SP2 78.10.2-8.27.1

suse advisories SUSE-SU-2021:1854-1

  • MozillaThunderbird openSUSE Leap 15.3 78.10.2-8.27.1

opensuse advisories openSUSE-SU-2021:1854-1

  • thunderbird Arch Linux 78.8.1-1

arch linux advisories AVG-1845

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-29950 updated cvss 7.5

Mozilla: Logic issue potentially leaves key material unlocked

  • Red Hat Enterprise Linux 6 thunderbird
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) thunderbird 78.9.1-1.el8_3
    fixed: vendor fix RHSA-2021:1193
  • Red Hat Enterprise Linux AppStream EUS (v. 8.1) thunderbird 78.9.1-1.el8_1
    fixed: vendor fix RHSA-2021:1190
  • Red Hat Enterprise Linux AppStream EUS (v. 8.2) thunderbird 78.9.1-1.el8_2
    fixed: vendor fix RHSA-2021:1201
  • Red Hat Enterprise Linux Client (v. 7) thunderbird 78.9.1-1.el7_9 Red Hat Enterprise Linux Server Optional (v. 7) thunderbird 78.9.1-1.el7_9 Red Hat Enterprise Linux Workstation (v. 7) thunderbird 78.9.1-1.el7_9
    fixed: vendor fix RHSA-2021:1192

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.85% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1673239 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • Mozilla Thunderbird

Classification

Weakness
  • CWE-312 Cleartext Storage of Sensitive Information

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.