CVE-2026-33526

Summary

Squid is a caching proxy for the Web. Prior to version 7.5, due to heap Use-After-Free, Squid is vulnerable to Denial of Service when handling ICP traffic. This problem allows a remote attacker to perform a reliable and repeatable Denial of Service attack against the Squid service using ICP protocol. This attack is limited to Squid deployments that explicitly enable ICP support (i.e. configure non-zero icp_port). This problem cannot be mitigated by denying ICP queries using icp_access rules. Version 7.5 contains a patch.

Affected Software

VendorProductVersion RangeStatus
squid-cachesquid< 7.5affected

Weaknesses

  • CWE-416: CWE-416: Use After Free
  • CWE-826: CWE-826: Premature Release of Resource During Expected Lifetime

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

squid: Squid: Denial of Service via heap Use-After-Free vulnerability in ICP handling

Additional References

References