CVE-2026-120639
Description
A flaw was found in perl-cgi, where it fails to properly validate newline characters when generating HTTP headers. When an application passes untrusted input into header fields, entity-encoded newlines or unvalidated parameters can bypass sanitization checks. A remote attacker could exploit this vulnerability to perform HTTP header injection or HTTP response splitting, potentially leading to cache poisoning, cross-site scripting (XSS), or session hijacking.
Statement
This vulnerability is rated Moderate because exploitation is limited to HTTP response splitting or header injection without directly compromising the underlying host or providing arbitrary code execution. Impact on Red Hat Enterprise Linux environments depends on deployed custom web applications that utilize perl-CGI to generate dynamic responses from untrusted user parameters. Systems running perl-CGI are only exposed if applications pass unvalidated client input into header generation routines or disable automatic entity escaping.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | Low | N/A | N/A |
| Integrity Impact | Low | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Application Data
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