Out-of-bounds read in Squid - CVE-2026-47729
Published: June 24, 2026
Vulnerability identifier: #VU135132
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-47729
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to disclose sensitive information.
The vulnerability exists due to improper validation of syntactic correctness of input in the FTP gateway when accessing a misbehaving FTP server through the gateway feature. A remote user can access a misbehaving FTP server through the gateway feature to disclose sensitive information.
The issue can cause an out-of-bounds read from random unrelated transactions.
Affected software
Squid
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP5
Debian Linux
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Real Time 15
Server Applications Module
openSUSE Leap
Ubuntu
openEuler
Fedora
squid (Ubuntu package)
squid-openssl (Ubuntu package)
squid
squid-debuginfo
squid-debugsource
squid (Debian package)
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP5
Debian Linux
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Real Time 15
Server Applications Module
openSUSE Leap
Ubuntu
openEuler
Fedora
squid (Ubuntu package)
squid-openssl (Ubuntu package)
squid
squid-debuginfo
squid-debugsource
squid (Debian package)
How to mitigate CVE-2026-47729
Install security update from vendor's website.
Squid - update to 7.6
squid (Ubuntu package) - addressed in versions 3.5.12-1ubuntu7.16+esm7, 3.5.27-1ubuntu1.14+esm6, 4.10-1ubuntu1.13+esm3, 5.9-0ubuntu0.22.04.7, 5.9-0ubuntu0.22.04.8, 6.14-0ubuntu0.24.04.4, 6.14-0ubuntu0.24.04.5, 6.14-0ubuntu0.25.10.4, 7.2-2ubuntu2.2
squid-openssl (Ubuntu package) - addressed in versions 5.9-0ubuntu0.22.04.8, 6.14-0ubuntu0.24.04.5
squid - update to 4.9-31
squid-debuginfo - update to 4.9-31
squid-debugsource - update to 4.9-31
squid-debugsource - addressed in versions 5.7-150400.3.41.1, 6.14-150600.3.20.1
squid-debuginfo - addressed in versions 5.7-150400.3.41.1, 6.14-150600.3.20.1
squid - addressed in versions 5.7-150400.3.41.1, 6.14-150600.3.20.1
squid - update to 7.6-1.fc44
squid (Debian package) - update to 6.13-2+deb13u2
squid (Ubuntu package) - addressed in versions 3.5.12-1ubuntu7.16+esm7, 3.5.27-1ubuntu1.14+esm6, 4.10-1ubuntu1.13+esm3, 5.9-0ubuntu0.22.04.7, 5.9-0ubuntu0.22.04.8, 6.14-0ubuntu0.24.04.4, 6.14-0ubuntu0.24.04.5, 6.14-0ubuntu0.25.10.4, 7.2-2ubuntu2.2
squid-openssl (Ubuntu package) - addressed in versions 5.9-0ubuntu0.22.04.8, 6.14-0ubuntu0.24.04.5
squid - update to 4.9-31
squid-debuginfo - update to 4.9-31
squid-debugsource - update to 4.9-31
squid-debugsource - addressed in versions 5.7-150400.3.41.1, 6.14-150600.3.20.1
squid-debuginfo - addressed in versions 5.7-150400.3.41.1, 6.14-150600.3.20.1
squid - addressed in versions 5.7-150400.3.41.1, 6.14-150600.3.20.1
squid - update to 7.6-1.fc44
squid (Debian package) - update to 6.13-2+deb13u2