Is CVE-2019-12527 being actively exploited?

CVE-2019-12527 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2019-12527?

CVE-2019-12527 has a CVSS 3.1 base score of 8.8 (HIGH).

CVE-2019-12527

HIGH · CVSS 8.8EPSS 49.0%EU EUVD

An issue was discovered in Squid 4.0.23 through 4.7. When checking Basic Authentication with HttpHeader::getAuth, Squid uses a global buffer to store the decoded data. Squid does not check that the decoded length isn't greater than the buffer, leading to a heap-based buffer overflow with user controlled data.

Key facts

CVSS score: 8.8 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-787
EPSS score: 49.0% (99th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2019-4122)
Published: July 11, 2019
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2019-4122 in the EU Vulnerability Database. Last updated in EUVD on August 4, 2024.

View on the EU Vulnerability Database

Affected products

canonical / ubuntu linux
canonical / ubuntu linux
canonical / ubuntu linux
debian / debian linux
fedoraproject / fedora
redhat / enterprise linux
redhat / enterprise linux eus
redhat / enterprise linux eus
redhat / enterprise linux eus
redhat / enterprise linux eus
redhat / enterprise linux server aus
redhat / enterprise linux server aus
redhat / enterprise linux server aus
redhat / enterprise linux server tus
redhat / enterprise linux server tus
redhat / enterprise linux server tus
squid-cache / squid

Certified products that may be affected

26 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

Red Hat Enterprise Linux 8 NSS Cryptographic Module - Red Hat, Inc. - FIPS 140 5513 - active
Red Hat Enterprise Linux 8 Kernel Cryptographic API - Red Hat, LLC - FIPS 140 5461 - active
Red Hat Enterprise Linux 8 Kernel Cryptographic API - Red Hat, Inc. - FIPS 140 5089 - active
Red Hat Enterprise Linux 8.6 - Red Hat, Inc. - Common Criteria CCEVS-VR-VID-11309-2024 - archived
Red Hat Enterprise Linux 8 OpenSSL Cryptographic Module - Red Hat®, Inc. - FIPS 140 4642 - historical

See all 26 in the Security Certifications Explorer.

References

http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00053.html(Broken Link)
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00056.html(Broken Link)
http://www.securityfocus.com/bid/109143(Broken Link, Third Party Advisory, VDB Entry)
http://www.squid-cache.org/Versions/v4/changesets/(Vendor Advisory)
http://www.squid-cache.org/Versions/v4/changesets/squid-4-7f73e9c5d17664b882ed32590e6af310c247f320.patch(Patch, Vendor Advisory)
https://access.redhat.com/errata/RHSA-2019:2593(Third Party Advisory)
https://github.com/squid-cache/squid/commits/v4(Patch, Third Party Advisory)
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPXN2CLAGN5QSQBTOV5IGVLDOQSRFNTZ/
https://seclists.org/bugtraq/2019/Aug/42(Mailing List, Third Party Advisory)
https://usn.ubuntu.com/4065-1/(Third Party Advisory)
https://www.debian.org/security/2019/dsa-4507(Third Party Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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