CVE-2026-120633: CGI versions before 5.00 for Perl trust the client X-Forwarded-Host header in url, self_url
Source GCVE Database
Not known to be exploited : upgrade to 5.00 soon.
Data as of 4 Nov 2026, 02:00 UTC
Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in 5.00
Exploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Upgrade CGI (Perl module) to 5.00.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| CGI | Affected
| Fixed in
|
CPANCGIpkg:cpan/CGIOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users should verify if a fixed version (5.00 or later) is available and upgrade accordingly. Until then, applications should not trust the X-Forwarded-Host header without validation or should ignore it when constructing URLs. Implementing strict validation or sanitization of this header before use can mitigate the risk.
Description
CGI versions before 5.00 for Perl trust the client-supplied X-Forwarded-Host header when constructing URLs such as url, self_url, virtual_host, and virtual_port. This header is used without validation, allowing an attacker to influence redirect locations, base hrefs, and form actions. This can lead to cache poisoning and the generation of URLs that point to attacker-controlled hosts.