CVE-2011-2766

7.5 HIGH 7% exploit odds Fix listed Auth & access Web app

What it is

The FCGI (aka Fast CGI) module 0.70 through 0.73 for Perl, as used by CGI::Fast, uses environment variable values from one request during processing of a later request, which allows remote attackers to bypass authentication via crafted HTTP headers.

At a glance

Exploitability: Can be exploited over the network without logging in. Limited direct impact.
Exploit odds: 7.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2011-09-23 10:55 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-16 23:31 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 7.2% in the next 30 days (EPSS).
Severity: 7.5 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2011-09-23 10:55 UTC
Last modified: 2026-06-16 23:31 UTC
Exploit probability: 7.2% · EPSS, next 30 days
Weakness: CWE-287 · Improper authentication
Record status: Modified

Affected

Fast Cgi Project Fast Cgi ≤ 0.73
Debian Linux 5.0
Debian Linux 6.0
Debian Linux 7.0

Attack profile CVSS 2.0 · 7.5

Attack vector: Network
Complexity: Low
Authentication: None
Confidentiality: Partial
Integrity: Partial
Availability: Partial

Raw vector

AV:N/AC:L/Au:N/C:P/I:P/A:P

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2011-2766.md and follow it. Check whether this project is affected by CVE-2011-2766. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record