CVE-2016-4555
client_side_request.cc in Squid 3.x before 3.5.18 and 4.x before 4.0.10 allows remote servers to cause a denial of service (crash) via crafted Edge Side Includes (ESI) responses.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 18.2%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.
Description
client_side_request.cc in Squid 3.x before 3.5.18 and 4.x before 4.0.10 allows remote servers to cause a denial of service (crash) via crafted Edge Side Includes (ESI) responses.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 18.17% probability · 97th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- squid-cache/squid · canonical/ubuntu linux · oracle/linux
- Source
- cve@mitre.org
EPSS moved from 18.2% on 6 October 2026 to 18.2% on 4 November 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
References
- http://bugs.squid-cache.org/show_bug.cgi?id=4455Exploit, Issue Tracking, Patch, Vendor Advisory
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
- http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
- http://www.debian.org/security/2016/dsa-3625
- http://www.openwall.com/lists/oss-security/2016/05/06/3Patch, Release Notes
- http://www.openwall.com/lists/oss-security/2016/05/06/5Patch, Third Party Advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.htmlThird Party Advisory
- http://www.securitytracker.com/id/1035770Third Party Advisory
- http://www.squid-cache.org/Advisories/SQUID-2016_9.txtVendor Advisory
- http://www.squid-cache.org/Versions/v3/3.4/changesets/SQUID-2016_9.patchPatch
- http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2016_9.patchPatch
- http://www.ubuntu.com/usn/USN-2995-1Third Party Advisory
- https://access.redhat.com/errata/RHSA-2016:1139
- https://access.redhat.com/errata/RHSA-2016:1140
- https://security.gentoo.org/glsa/201607-01
- http://bugs.squid-cache.org/show_bug.cgi?id=4455Exploit, Issue Tracking, Patch, Vendor Advisory
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
- http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
- http://www.debian.org/security/2016/dsa-3625
- http://www.openwall.com/lists/oss-security/2016/05/06/3Patch, Release Notes
- http://www.openwall.com/lists/oss-security/2016/05/06/5Patch, Third Party Advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.htmlThird Party Advisory
- http://www.securitytracker.com/id/1035770Third Party Advisory
- http://www.squid-cache.org/Advisories/SQUID-2016_9.txtVendor Advisory
- http://www.squid-cache.org/Versions/v3/3.4/changesets/SQUID-2016_9.patchPatch
- http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2016_9.patchPatch
- http://www.ubuntu.com/usn/USN-2995-1Third Party Advisory
- https://access.redhat.com/errata/RHSA-2016:1139
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.