Denial of service in Perl CGI::Cookie through crafted expires value
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::Cookie for Perl from 4.67 before 5.00 is affected. The parse function inserts the cookie's expires value unescaped into a regex, so a crafted value causes an invalid pattern or excessive backtracking (CWE-1333). A client can send a crafted Cookie header that makes the request die or ties up the process, causing denial of service.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
Description from the CNA
CGI::Cookie versions from 4.67 before 5.00 for Perl allow denial of service via the client cookie expires value used as a regex in parse. CGI's cookie method reads the Cookie request header through parse, which interpolates the header's expires value unescaped into the substitution pattern that removes it from the cookie string. A client can make the request die with an invalid pattern, or tie up the process with one that backtracks catastrophically.
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 | 4.67 to before 5.00 | 5.00 | Patch available | CNA |
- CGI Vendor— Affected 4.67 to before 5.00 Fixed in 5.00 Patch available CNA
Remediation
Update CGI to version 5.00, which fixes the flaw. Red Hat Enterprise Linux 7, 8, 9 and 10 are affected, and the sources list no fixed version for them.
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: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Timeline
- 2026-11-03 Threatist record created from CVE-2026-120631
- 2026-11-04 Affected versions changed · Red Hat
- 2026-11-04 CVSS score added · Red Hat
- 2026-11-04 Alias added: GHSA-v4gh-jwmf-g38j
References
Sources
- CVE-2026-120631 · CVE Program
- CVE-2026-120631 · NVD
- FIRST EPSS
- GHSA-v4gh-jwmf-g38j · GitHub Advisory Database · CC BY 4.0
- CVE-2026-120631 · Red Hat security data · CC BY 4.0
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