Quick answers
- Is CVE-2026-120642 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-120642 being exploited in the wild.
- How severe is CVE-2026-120642?
- Informational severity, published 4 November 2026.
- Which products and versions are affected?
- Perl CGI before 5.00.
- Is there a fix for CVE-2026-120642?
- Yes: fixed in 5.00. Until then: Until upgrading to CGI 5.00, applications must explicitly untaint request-derived values (upload filenames, cookie names, URL parameter names, path_info, script_name, and Accept results) before using them in taint-sensitive operations such as open() or system() calls. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-120642 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-120642?
- 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
Until upgrading to CGI 5.00, applications must explicitly untaint request-derived values (upload filenames, cookie names, URL parameter names, path_info, script_name, and Accept results) before using them in taint-sensitive operations such as open() or system() calls.
Technical details
The CGI module returned request-derived values (upload filenames, uploadInfo headers, path_info, script_name, Accept types, and cookie/url_param name lists) without Perl's taint flag because they were extracted via regex captures or used as hash keys, neither of which taints in Perl. An attacker who controls request data can exploit this to bypass -T mode checks and pass untainted malicious input to functions like open() or system() if the application does not re-taint the values. The fix applies the taint flag to these values in version 5.00.
Affected products
- Perl CGI before 5.00
Timeline
- 2026-11-04: disclosed