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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | squid | 4.1-1 | — |
| Debian 13 | squid | 4.1-1 | — |
| Debian 12 | squid | 4.1-1 | — |
| Debian 8 | squid3 | 3.4.8-6+deb8u3 | DSA-3625-1 |
| Debian 7 | squid | 2.7.STABLE9-4.1+deb7u2 | DLA-558-1 |
| Debian 7 | squid3 | 3.1.20-2.2+deb7u5 | DLA-478-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | squid3 | 3.5.12-1ubuntu7.2 | USN-2995-1 |
| Ubuntu 14.04 LTS | squid3 | 3.3.8-1ubuntu6.8 | USN-2995-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | squid +1 | 7:3.3.8-26.el7_2.3 | RHSA-2016:1139 |
| RHEL 6 | squid | 7:3.1.23-16.el6_8.4 | RHSA-2016:1138 |
| RHEL 6 | squid34 | 7:3.4.14-9.el6_8.3 | RHSA-2016:1140 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP1 | squid | 3.3.14-20.2 | SUSE-SU-2016:2008-1 |
| SLES 11 SP4 | squid | 2.7.STABLE5-2.12.29.1 | SUSE-SU-2016:2147-1 |
| SLES 11 SP4 | squid3 | 3.1.23-8.16.30.1 | SUSE-SU-2016:2089-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP1 | squid | 3.3.14-20.2 | SUSE-SU-2016:2008-1 |
| SLES for SAP 11 SP4 | squid | 2.7.STABLE5-2.12.29.1 | SUSE-SU-2016:2147-1 |
| SLES for SAP 11 SP4 | squid3 | 3.1.23-8.16.30.1 | SUSE-SU-2016:2089-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | squid +1 | 7:3.3.8-26.el7_2.3 | ELSA-2016-1139 |
Advisories 11
- RHSA-2016:1140 Red Hat Security Advisory: squid34 security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2016:1139 Red Hat Security Advisory: squid security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2016:1138 Red Hat Security Advisory: squid security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DLA-558-1 squid - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-478-1 squid3 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3625-1 squid3 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-2995-1 squid3 vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2016:2008-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2089-1 Security update for squid3 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2147-1 Security update for squid SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2016-1139 Moderate: squid security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · May 31, 2016
References
- GLSA-201607-01 vendor-advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
- http://www.squid-cache.org/Versions/v3/3.3/changesets/SQUID-2016_8.patch
- http://www.squid-cache.org/Versions/v3/3.4/changesets/SQUID-2016_8.patch
- SUSE-SU-2016:1996 vendor-advisory
- http://www.squid-cache.org/Versions/v3/3.1/changesets/SQUID-2016_8.patch
- USN-2995-1 vendor-advisory
- 1035769 vdb-entry
- http://www.squid-cache.org/Versions/v3/3.2/changesets/SQUID-2016_8.patch
- RHSA-2016:1140 vendor-advisory
- openSUSE-SU-2016:2081 vendor-advisory
- RHSA-2016:1138 vendor-advisory
- RHSA-2016:1139 vendor-advisory
- http://www.squid-cache.org/Advisories/SQUID-2016_8.txt
- SUSE-SU-2016:2089 vendor-advisory
- http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2016_8.patch
- DSA-3625 vendor-advisory