CVE-2026-32748
Description
A flaw was found in Squid. A remote attacker can exploit this vulnerability by sending specially crafted ICP (Internet Cache Protocol) traffic. This can lead to a Denial of Service (DoS) due to premature resource release and use-after-free vulnerabilities. This attack is possible in Squid deployments with explicitly enabled ICP support.
Statement
This Important flaw in Squid can lead to a Denial of Service when processing specially crafted Internet Cache Protocol (ICP) traffic. This vulnerability affects Red Hat products running Squid if ICP support is explicitly enabled by configuring a non-zero icp_port. Deployments where ICP is not enabled by default are not affected.
Mitigation
To mitigate this issue, ensure that ICP support is not explicitly enabled in the Squid configuration. This can be achieved by commenting out or setting `icp_port` to `0` in the `squid.conf` file. After modifying the configuration, the Squid service must be reloaded or restarted for the changes to take effect.
Example:
# icp_port 3130or
icp_port 0Warning: Reloading or restarting the Squid service may temporarily interrupt proxy services.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 7.5 | 7.5 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Memory
If the released resource is subsequently reused or reallocated, then a read operation on the original resource might access sensitive data that is associated with a different user or entity.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
When the resource is released, the software might modify some of its structure, or close associated channels (such as a file descriptor). When the software later accesses the resource as if it is valid, the resource might not be in an expected state, leading to resultant errors that may lead to a crash.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands; Modify Application Data; Modify Memory
When the resource is released, the software might modify some of its structure. This might affect logic in the sections of code that still assume the resource is active. If the released resource is related to memory and is used in a function call, or points to unexpected data in a write operation, then code execution may be possible upon subsequent accesses.
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