CVE-2021-39242

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

Description

An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It can lead to a situation with an attacker-controlled HTTP Host header, because a mismatch between Host and authority is mishandled.

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-2021-39242

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-39242.html

OS impact

OSVersionStatusFixed in
arch archfixed2.4.3-1
suse slesaffected
debian debianbookwormfixed2.2.16-1
debian debianbullseyefixed2.2.9-2+deb11u1
debian debianforkyfixed2.2.16-1
debian debiansidfixed2.2.16-1
debian debiantrixiefixed2.2.16-1

References

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