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Fencer Vulns
critical 9.8

CVE-2021-29978 json

Multiple low security issues were discovered and fixed in a security audit of Mozilla VPN 2.x branch as part of a 3rd party security audit.

published 2021-08-05 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-16437

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.8%
EPSS 2.8% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

Multiple low security issues were discovered and fixed in a security audit of Mozilla VPN 2.x branch as part of a 3rd party security audit. This vulnerability affects Mozilla VPN < 2.3.

Patch / fix

  • Mozilla Mozilla VPN 2.3

Exploit prediction

2.78% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/mozilla-mobile/mozilla-vpn-client/issues/799 referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/mozilla-mobile/mozilla-vpn-client/issues/800 referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/mozilla-mobile/mozilla-vpn-client/issues/806 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C

Affected products

  • Mozilla Mozilla VPN

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.