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Vulnerability record · CVE-2016-2569 · published 27 February 2016

CVE-2016-2569: Squid-cache squid improper input validation vulnerability

Squid Cache · Squid

Squid 3.x before 3.5.15 and 4.x before 4.0.7 does not properly append data to String objects, which allows remote servers to cause a denial of service (assertion failure and daemon exit) via a long string, as demonstrated by a crafted HTTP Vary header.

7.5 CVSS 3.0 High EPSS 31% · top 1.8% CWE-20 · Improper input validation
7.5CVSS 3.0 base score, v2 5.0
31%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
22References
17 Jun 2026Last modified by NVD

Description

Squid 3.x before 3.5.15 and 4.x before 4.0.7 does not properly append data to String objects, which allows remote servers to cause a denial of service (assertion failure and daemon exit) via a long string, as demonstrated by a crafted HTTP Vary header.

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
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://rhn.redhat.com/errata/RHSA-2016-2600.html
http://www.openwall.com/lists/oss-security/2016/02/26/2
http://www.securitytracker.com/id/1035101
http://www.squid-cache.org/Advisories/SQUID-2016_2.txt Vendor Advisory
http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-13991.patch
http://www.squid-cache.org/Versions/v4/changesets/squid-4-14552.patch
https://security.gentoo.org/glsa/201607-01
https://usn.ubuntu.com/3557-1/
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://rhn.redhat.com/errata/RHSA-2016-2600.html
http://www.openwall.com/lists/oss-security/2016/02/26/2
http://www.securitytracker.com/id/1035101
http://www.squid-cache.org/Advisories/SQUID-2016_2.txt Vendor Advisory
http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-13991.patch
http://www.squid-cache.org/Versions/v4/changesets/squid-4-14552.patch
https://security.gentoo.org/glsa/201607-01
https://usn.ubuntu.com/3557-1/

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2016-2569), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.