CVE-2020-12403

medium
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
5.5

Description

A flaw was found in the way CHACHA20-POLY1305 was implemented in NSS in versions before 3.55. When using multi-part Chacha20, it could cause out-of-bounds reads. This issue was fixed by explicitly disabling multi-part ChaCha20 (which was not functioning correctly) and strictly enforcing tag length. The highest threat from this vulnerability is to confidentiality and system availability.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2020-12403

vendor Authored 2026-05-27

Vendor advisory: rocky — https://errata.rockylinux.org/RLSA-2021:0538

OS impact

OSVersionStatusFixed in
rockylinux rocky8fixed
debian debianbookwormfixed2:3.55-1
debian debianbullseyefixed2:3.55-1
debian debianforkyfixed2:3.55-1
debian debiansidfixed2:3.55-1
debian debiantrixiefixed2:3.55-1

References

Verify integrity in audit chain (admin only). AS-IS.