VulnerabilityPublished 4 Nov 2026

CVE-2026-120647: CGI versions before 5.00 for Perl allow Content-Disposition parameter injection via unescaped double

Source GCVE Database

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Authoritative record:CVE-2026-120647· Medium

Not known to be exploited : upgrade to 5.00 when convenient.

Data as of 4 Nov 2026, 01:58 UTC

Severity

Medium

Rated Medium 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-599q-wvvm-v4wp

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

If you cannot patch yet, avoid passing untrusted input directly as the attachment filename or implement manual escaping of double quotes in the filename parameter.

Description

CGI versions before 5.00 for Perl contain a vulnerability where the Content-Disposition header's attachment filename parameter is susceptible to injection via unescaped double quotes. This allows an attacker to inject a second filename parameter by manipulating the attachment name, potentially altering the filename under which the response is saved.

Impact

This vulnerability can lead to unintended filename manipulation in HTTP responses, which may cause confusion or facilitate further attacks depending on how the filename is used by clients or downstream systems. However, no direct exploitation in the wild or further impact details are provided.

Summary

The CGI Perl module versions prior to 5.00 do not properly escape double quotes in the attachment filename parameter of the Content-Disposition header. Specifically, the header(-attachment => $name) function writes the $name value directly into the quoted filename parameter without escaping embedded double quotes. If an application uses request data as the attachment name, an attacker can inject a second filename parameter, changing the filename used when saving the response.

CWE-116Improper Encoding or Escaping of Output (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A05:2025: Injection (opens in a new tab)
The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Parameterization
If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
Architecture and Design · Implementation
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
OWASP Cheat Sheets
Content Security Policy (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
Query Parameterization (opens in a new tab)
OWASP ASVS 4.0.3
V14.4.6 (opens in a new tab)
V14.4.4 (opens in a new tab)
V14.4.2 (opens in a new tab)
Attack patterns
Cross Zone Scripting (opens in a new tab)
User-Controlled Filename (opens in a new tab)
Web Server Logs Tampering (opens in a new tab)
AJAX Footprinting (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, 01:58 UTC

WeaknessesCWE-116

Technical details

References

Community reviews

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