CVE-2026-115347
Description
A flaw was found in mistune. A remote attacker can exploit an inefficient algorithmic complexity issue in the link text parsing logic by submitting specially crafted Markdown input containing long sequences of unmatched square brackets. Processing this input causes repeated forward scans, leading to excessive resource consumption and a Denial of Service (DoS) that stalls application worker processes.
Statement
Red Hat rates this vulnerability as Important because unauthenticated remote attackers can trigger severe denial of service against applications that parse untrusted markdown without requiring prior system access. By submitting payloads with long sequences of unbalanced brackets, an attacker induces quadratic parsing complexity that exhausts CPU resources and hangs backend worker processes. In Red Hat OpenShift Container Platform and Red Hat OpenShift AI deployments, this resource starvation can stall shared workbench pods and pipeline runtimes, disrupting multi-tenant service availability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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 | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU)
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
