CVE-2026-33515: Squid is a caching proxy for the Web

Q: How do I fix CVE-2026-33515?

squid: upgrade to 7.5. Exact commands for each OS are on this page.

Q: Is CVE-2026-33515 being exploited?

CVE-2026-33515 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-33515 affect?

CVE-2026-33515 affects squid. Severity is medium (CVSS 6.5). Squid is a caching proxy for the Web. Prior to version 7.5, due to improper input validation, Squid is vulnerable to out of bounds read when handling ICP traffic. This problem allows a remote attacker to receive small amounts of memory pote

Q: How urgent is CVE-2026-33515?

Priority 44/100. Remotely exploitable, no login, no user action

This month

MEDIUM 6.5REMOTEUPGRADE

CVE-2026-33515 is a medium-severity flaw (CVSS 6.5) affecting squid. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Squid is a caching proxy for the Web. Prior to version 7.5, due to improper input validation, Squid is vulnerable to out of bounds read when handling ICP traffic. This problem allows a remote attacker to receive small amounts of memory potentially containing sensitive information when responding with errors to invalid ICP requests. This attack is limited to Squid deployments that explicitly enable ICP support (i.e. configure non-zero `icp_port`).

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 36%)
CISA exploited list	No
Weakness	CWE-125, CWE-1289
Published	2026-03-26
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: squid-cache

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-26 01:16 UTCPublished CVE record published
2026-06-17 10:37 UTCUpdated Record last modified

squid-cache squid UPGRADE

Affected: < 7.5

Fixed in: 7.5

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy squid || rpm -q squid || squid --version

2. UPGRADE to 7.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade squid

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade squid

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-33515?

squid: upgrade to 7.5. Exact commands for each OS are on this page.

Is CVE-2026-33515 being exploited?

CVE-2026-33515 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-33515 affect?

CVE-2026-33515 affects squid. Severity is medium (CVSS 6.5). Squid is a caching proxy for the Web. Prior to version 7.5, due to improper input validation, Squid is vulnerable to out of bounds read when handling ICP traffic. This problem allows a remote attacker to receive small amounts of memory pote

How urgent is CVE-2026-33515?

Priority 44/100. Remotely exploitable, no login, no user action

Software pages

Squid vulnerabilities

Related CVEs

CVE-2026-47729 MEDIUM 6.5 UPGRADE Squid is a caching proxy for the Web
CVE-2026-50012 MEDIUM 5.5 UPGRADE Squid is a caching proxy for the Web
CVE-2026-33526 HIGH 7.5 UPGRADE Squid is a caching proxy for the Web
CVE-2026-32748 HIGH 7.5 UPGRADE Squid is a caching proxy for the Web

References

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