Open redirect and script injection in Perl CGI via REQUEST_URI
Key facts
- Attack vector
- —
- Privileges required
- —
- User interaction
- —
- Attack complexity
- —
- Impact type
- Spoofing, Cross-site scripting
- Confidentiality · integrity · availability
- —
- Fix status
- Partial Red Hat: 4 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat. Impact type from CWE-601 and CWE-79.
Summary
CGI for Perl before 5.00 builds URLs from the client-supplied REQUEST_URI without validation, as in url() and the default start_form action (CWE-601). The resulting URL can be protocol-relative, absolute-form or contain backslashes, so links and form posts can lead to another host. With url(-relative=>1) the result can also be a javascript: URL, which allows script injection (CWE-79).
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
Description from the CNA
CGI versions before 5.00 for Perl allow open redirects and script injection via URLs built from REQUEST_URI in url and start_form. url(-absolute=>1), url(-relative=>1) and the default start_form action are built from the client-supplied REQUEST_URI without validation. The result can be protocol-relative (//evil.example), absolute-form (http://evil.example/) or contain backslashes, and url(-relative=>1) can return a javascript: URL. Links and form posts built from these URLs can go to another host.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | CGI | before 5.00 | 5.00 | Patch available | CNA |
- CGI Vendor— Affected before 5.00 Fixed in 5.00 Patch available CNA
Remediation
CGI for Perl is fixed in version 5.00. Red Hat lists Red Hat Enterprise Linux 7, 8, 9 and 10 as affected without a fix and with no fix plan available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
- Fix · CNA CGI Fixed in 5.00
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-11-03 Threatist record created from CVE-2026-120636
- 2026-11-04 Affected versions changed · Red Hat
- 2026-11-04 CVSS score added · Red Hat
- 2026-11-04 Alias added: GHSA-7432-xjrv-h264
References
Sources
- CVE-2026-120636 · CVE Program
- CVE-2026-120636 · NVD
- FIRST EPSS
- GHSA-7432-xjrv-h264 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-120636 · Red Hat security data · CC BY 4.0
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