Denial of service in Perl CGI via symbolic reference in uploadInfo
Key facts
- Attack vector
- —
- Privileges required
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- User interaction
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- Attack complexity
- —
- Impact type
- —
- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 4 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
CGI for Perl from 4.71 before 5.00 allows denial of service. The uploadInfo function dereferences its argument and calls a method on it without checking that it is an upload filehandle. A plain string naming a defined global variable, such as a crafted upload parameter value, is treated as a symbolic reference, and the method call dies (CWE-843).
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
CGI versions from 4.71 before 5.00 for Perl allow denial of service via a plain string dereferenced as a symbolic reference in uploadInfo. uploadInfo dereferences its argument and calls its filename method without checking that it is an upload filehandle. A plain string naming a defined global variable, such as the parameter value from ?upload=0, is treated as a symbolic reference, and the method call on it dies.
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 | 4.71 to before 5.00 | 5.00 | Patch available | CNA |
- CGI Vendor— Affected 4.71 to before 5.00 Fixed in 5.00 Patch available CNA
Remediation
Upgrade CGI to version 5.00. Red Hat lists Red Hat Enterprise Linux 10, 7, 8 and 9 as affected with no fix plan available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- 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-2026-120646
- 2026-11-04 Affected versions changed · Red Hat
- 2026-11-04 CVSS score added · Red Hat
- 2026-11-04 Alias added: GHSA-qfrv-79gg-33h6
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score changed · Red Hat
References
Sources
- CVE-2026-120646 · CVE Program
- CVE-2026-120646 · NVD
- FIRST EPSS
- GHSA-qfrv-79gg-33h6 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-120646 · Red Hat security data · CC BY 4.0
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