SB2026062448 - Debian update for squid
Published: June 24, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Out-of-bounds read (CVE-ID: CVE-2026-33515)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper input validation in ICP message handling when processing ICP traffic. A remote attacker can send a specially crafted ICP request to disclose small amounts of memory potentially containing sensitive information.
The attack is limited to Squid deployments that explicitly enable ICP support (i.e., configure a non-zero icp_port).
2) Use After Free (CVE-ID: CVE-2026-33526)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to heap use-after-free in ICP request handling when processing ICP traffic. A remote attacker can send a specially crafted ICP request to cause a denial of service.
The attack is limited to Squid deployments that have ICP support enabled via a non-zero icp_port configuration.
3) Out-of-bounds read (CVE-ID: CVE-2026-47729)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 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/E:U/U:Clear
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.
4) Heap-based buffer overflow (CVE-ID: CVE-2026-50012)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a remote user to cause a denial of service and modify memory.
The vulnerability exists due to heap-based buffer overflow in cache_digest reply handling when processing maliciously crafted replies to cache_digest request messages. A remote privileged user can send a specially crafted reply to cause a denial of service and modify memory.
Only instances compiled with the --enable-cache-digests option are vulnerable, and exploitation requires a trusted peer relationship over TCP.
Remediation
Install update from vendor's website.