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Vulnerability record · CVE-2019-12526 · published 26 November 2019

CVE-2019-12526: Squid-cache squid out-of-bounds write vulnerability

Squid Cache · Squid

An issue was discovered in Squid before 4.9. URN response handling in Squid suffers from a heap-based buffer overflow. When receiving data from a remote server in response to an URN request, Squid fails to ensure that the response can fit within the buffer. This leads to attacker controlled data overflowing in the heap.

9.8 CVSS 3.1 Critical EPSS 20% · top 2.6% CWE-787 · Out-of-bounds write
9.8CVSS 3.1 base score, v2 7.5
20%EPSS exploitation probability, 30 days
NoNot in CISA KEV
5Affected product versions listed by NVD
18References
17 Jun 2026Last modified by NVD

Description

An issue was discovered in Squid before 4.9. URN response handling in Squid suffers from a heap-based buffer overflow. When receiving data from a remote server in response to an URN request, Squid fails to ensure that the response can fit within the buffer. This leads to attacker controlled data overflowing in the heap.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

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

References

LinkTags
http://www.squid-cache.org/Advisories/SQUID-2019_7.txt Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1156326 Issue TrackingThird Party Advisory
https://lists.debian.org/debian-lts-announce/2019/12/msg00011.html Mailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MTM74TU2BSLT5B3H4F3UDW5
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UEMOYTMCCFWK5NOXSXEIH5D
https://security.gentoo.org/glsa/202003-34 Third Party Advisory
https://usn.ubuntu.com/4213-1/ Third Party Advisory
https://www.debian.org/security/2020/dsa-4682 Third Party Advisory
http://www.squid-cache.org/Advisories/SQUID-2019_7.txt Third Party Advisory
https://bugzilla.suse.com/show_bug.cgi?id=1156326 Issue TrackingThird Party Advisory
https://lists.debian.org/debian-lts-announce/2019/12/msg00011.html Mailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html Mailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MTM74TU2BSLT5B3H4F3UDW5
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UEMOYTMCCFWK5NOXSXEIH5D
https://security.gentoo.org/glsa/202003-34 Third Party Advisory
https://usn.ubuntu.com/4213-1/ Third Party Advisory
https://www.debian.org/security/2020/dsa-4682 Third Party Advisory

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Source: NIST National Vulnerability Database (record CVE-2019-12526), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.