Perl CGI denial of service via regex from request values in scrolling_list
Key facts
- Attack vector
- —
- Privileges required
- —
- User interaction
- —
- Attack complexity
- —
- Impact type
- Denial of service
- 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-1333.
Summary
CGI versions before 5.00 for Perl allow denial of service through submitted values used as a regex for optgroup selection in scrolling_list. When rendering option groups, scrolling_list marks selected options by interpolating each selected value, taken by default from request parameters, unescaped into a substitution pattern. A client can make the request die with an invalid pattern, or tie up the process with one that backtracks heavily. The weaknesses are CWE-1333 and CWE-625.
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 denial of service via submitted values used as a regex for optgroup selection in scrolling_list. When rendering option groups, scrolling_list marks the selected options by interpolating each selected value, by default taken from the request parameters, unescaped into a substitution pattern. A client can make the request die with an invalid pattern, or tie up the process with one that backtracks heavily.
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
Upgrade CGI for Perl to version 5.00 or later. Red Hat rates this Moderate and reports no fix plan yet for Red Hat Enterprise Linux 7, 8, 9 or 10.
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-2026-120645
- 2026-11-04 Affected versions changed · Red Hat
- 2026-11-04 CVSS score added · Red Hat
- 2026-11-04 Alias added: GHSA-8xqm-fm8j-xv84
References
Sources
- CVE-2026-120645 · CVE Program
- CVE-2026-120645 · NVD
- FIRST EPSS
- GHSA-8xqm-fm8j-xv84 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-120645 · Red Hat security data · CC BY 4.0
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