Is CVE-2026-120647 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-120647 being exploited in the wild.

How severe is CVE-2026-120647?

Informational severity, published 4 November 2026.

Is there a fix for CVE-2026-120647?

Yes: fixed in 5.00. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-120647 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-120647?

Check whether you run Perl CGI at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-120647: Perl CGI header attachment parameter injection

CVE-2026-120647 · Severity: info · Published 2026-11-04

The CGI module for Perl, a library that helps web applications generate HTTP responses, does not properly escape special characters in file attachment filenames. An attacker can inject additional HTTP header parameters by crafting a malicious filename, potentially tricking users' browsers into downloading files with different names or triggering other header-based attacks.

Technologies: Perl CGI. Vendors: Perl.

Quick answers

Is CVE-2026-120647 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-120647 being exploited in the wild.
How severe is CVE-2026-120647?: Informational severity, published 4 November 2026.
Which products and versions are affected?: Perl CGI before 5.00.
Is there a fix for CVE-2026-120647?: Yes: fixed in 5.00. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-120647 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-120647?: Check whether you run Perl CGI at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 5.00

Technical details

The vulnerability is a parameter injection in the Content-Disposition header caused by failure to escape double quotes and backslashes in the filename parameter. When an application passes untrusted request data to header(-attachment => $name), unescaped quotes allow an attacker to inject additional parameters (e.g., a second filename= parameter) per RFC 9110 quoted-string syntax. The fix (version 5.00+) escapes " and \ characters in the filename value.

Affected products

Perl CGI before 5.00

Timeline

2026-11-04: disclosed
2026-11-02: patched

References

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