CVE-2026-32748Network attack vector

Service interruption via stale ICP request reuse

Published Mar 26, 2026 · Updated Mar 26, 2026

Use-after-free in Squid before 7.5 allows remote attackers to interrupt the proxy service by sending ICPv3 queries to an enabled ICP port. In ICPv3 request handling, ACLFilledChecklist releases an unlocked HttpRequest, and Squid dereferences the destroyed object after icpAccessAllowed returns. The attack requires a nonzero icp_port, needs no authentication, and repeatedly interrupts the proxy even when icp_access rules deny queries.

CVSS severity8.7
High
EPSS probability8.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Squid before 7.5 allows remote attackers to interrupt the proxy service by sending ICPv3 queries to an enabled ICP port. In ICPv3 request handling, ACLFilledChecklist releases an unlocked HttpRequest, and Squid dereferences the destroyed object after icpAccessAllowed returns. The attack requires a nonzero icp_port, needs no authentication, and repeatedly interrupts the proxy even when icp_access rules deny queries.

The record

CVE
CVE-2026-32748
Published
Mar 26, 2026
Updated
Mar 26, 2026
Vendor
Squid Software Foundation
Product
Squid
Classifications
CWE-826, CWE-413, CWE-416, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 7.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Squid Software Foundation · Squidversion=< 7.5

Published CVSS scores

8.7GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-826Premature Release of Resource During Expected Lifetime
CWE-413Improper Resource Locking
CWE-416Use After Free
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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