CVE-2026-120634
Description
A flaw was found in perl-cgi. When running in persistent server environments, the internal buffer used to forward warnings to the browser is not cleared between requests. Consequently, a user can view sensitive request data or error details from another user's session in the returned HTML comments, leading to information disclosure.
Statement
This vulnerability is rated as having a Moderate impact because it only leads to low-impact information disclosure without compromising system integrity or service availability. Exposure requires non-default, persistent execution setups such as mod_perl, FastCGI, or PSGI, paired with explicit use of CGI::Carp browser warning routines. Traditional short-lived CGI environments that spawn a fresh process for each HTTP transaction are entirely unaffected, as memory buffers are discarded upon request completion. Furthermore, exploitation is contingent on sensitive contextual data being captured within generated script warnings.
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 | 5.3 | 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 | None | 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:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Data can "bleed" from one session to another through member variables of singleton objects, such as Servlets, and objects from a shared pool. Storing user data in Servlet member fields introduces a data access race condition.
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