VulnerabilityPublished 4 Nov 2026

CVE-2026-120641: CGI versions before 5.00 for Perl return upload filenames with any client-supplied path, including

Source GCVE Database

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Authoritative record:CVE-2026-120641· High

Not known to be exploited : upgrade to 5.00 soon.

Data as of 4 Nov 2026, 01:59 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in 5.00

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-3hqq-f8xf-6qwx

What to do

Upgrade CGI (Perl module) to 5.00.

Affected software

Product	Affected	Fixed in
CGI	Affected <5.00	Fixed in 5.00
CPANCGI`pkg:cpan/CGI`Other threats	Affected <5.00	Fixed in 5.00

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Users should implement input validation or sanitization to remove path components from uploaded filenames before saving files. If you cannot patch yet, applications must not trust the filename parameter from the Content-Disposition header and should enforce safe file storage paths.

Description

CGI versions for Perl prior to 5.00 return uploaded filenames including any client-supplied path segments, such as ../ or Windows-style paths. This means the filename is taken directly from the Content-Disposition header without sanitization. Applications that save uploaded files using this name risk writing files outside the intended directory.

Impact

An attacker can supply a crafted filename with path traversal sequences to cause the application to write files outside the intended directory. This can lead to overwriting or creating files in arbitrary locations on the server, which may result in unauthorized file modification or code execution depending on the application context.

Summary

The vulnerability in CGI versions before 5.00 for Perl involves returning the upload filename exactly as provided by the client in the Content-Disposition header, including any path components like '../' or Windows paths. This lack of sanitization can lead to directory traversal when an application saves the uploaded file using this name, potentially allowing files to be written outside the designated upload directory.

CWE-22Improper Limitation of a Pathname to a Restricted Directory (Path Traversal) (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.1 (opens in a new tab)
Attack patterns
Path Traversal (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
Using Escaped Slashes in Alternate Encoding (opens in a new tab)
Using Slashes in Alternate Encoding (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2026, 01:59 UTC

WeaknessesCWE-22

Technical details

References

Community reviews

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