CVE-2023-50269
SQUID-2023:10 Denial of Service in HTTP Request parsing
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Description
Squid is a caching proxy for the Web. Due to an Uncontrolled Recursion bug in versions 2.6 through 2.7.STABLE9, versions 3.1 through 5.9, and versions 6.0.1 through 6.5, Squid may be vulnerable to a Denial of Service attack against HTTP Request parsing. This problem allows a remote client to perform Denial of Service attack by sending a large X-Forwarded-For header when the follow_x_forwarded_for feature is configured. This bug is fixed by Squid version 6.6. In addition, patches addressing this problem for the stable releases can be found in Squid's patch archives.
Official description from the CVE record, published by GitHub_M. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 3.1 High 8.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Scope: Changed
The impact can reach other components beyond the vulnerable one.
Confidentiality impact: None
No effect on the secrecy of data.
Integrity impact: None
No effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Scope | Changed | The impact can reach other components beyond the vulnerable one. |
| Confidentiality impact | None | No effect on the secrecy of data. |
| Integrity impact | None | No effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
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EPSS
- Score
- 0.57627 (57.6% probability)
- Percentile
- 99.1%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA assessment as of Dec 19, 2023
- Automatable
- yes
- Technical impact
- partial
Weakness (CWE)
- CWE-674Uncontrolled Recursion
Affected products
squid-cache squid
- affected: >= 2.6, <= 2.7.STABLE9
- affected: >= 3.1, <= 5.9
- affected: >= 6.0.1, < 6.6
References
- github.com/squid-cache/squid/security/advisories/GHSA-wgq4-…
- squid-cache.org/Versions/v5/SQUID-2023_10.patch
- squid-cache.org/Versions/v6/SQUID-2023_10.patch
- lists.fedoraproject.org/archives/list/package-announce@list…
- lists.fedoraproject.org/archives/list/package-announce@list…
- lists.debian.org/debian-lts-announce/2024/01/msg00003.html
- security.netapp.com/advisory/ntap-20240119-0005
Timeline
- ID reserved
- Record published
- Record last updated
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About CubePath
Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:52 UTC. Sources and licenses