CVE-2016-4554

high
Published 2016-05-10 ยท Modified 2026-05-06
CVSS v3
8.6
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
CVSS v4 NEW
โ€”
not yet in upstream
VIR risk
8.6

Description

mime_header.cc in Squid before 3.5.18 allows remote attackers to bypass intended same-origin restrictions and possibly conduct cache-poisoning attacks via a crafted HTTP Host header, aka a "header smuggling" issue.

Predictions

Exploit likelihood
91%
Patch ETA
โ€”

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ€” if you've already worked around this in production โ€” publish your fix to the community-verified tier.

โœš Propose a mitigation on Community โ†’ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

OSVersionStatusFixed in
suse slesaffected
ubuntu ubuntu12.04affected
ubuntu ubuntu14.04affected
ubuntu ubuntu15.10affected
ubuntu ubuntu16.04affected
debian debianbookwormfixed4.1-1
debian debianbullseyefixed4.1-1
debian debianforkyfixed4.1-1
debian debiansidfixed4.1-1
debian debiantrixiefixed4.1-1

Application impact

VendorProductVersionsFixed
squid-cachesquid{"endIncluding":"3.5.17"}

References

CWEs

CWE-345

Community-verified mitigations for this CVE will appear above when contributors publish them.

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