CVE-2026-85150

Description

A NULL pointer dereference flaw was found in GStreamer's RTSP support library. The vulnerability occurs while parsing an Authorization or WWW-Authenticate header that uses Digest authentication. Specially crafted whitespace placement around a parameter's terminator can cause an internal length calculation to underflow, leading to a crash of the process parsing the header. On an RTSP server this can be triggered by a remote, unauthenticated attacker sending a single malformed request when the server has authentication enabled; the same flaw can also be triggered against an RTSP client by a malicious or compromised RTSP server. Successful exploitation results in a denial of service (application crash) and has no confirmed impact on confidentiality or integrity.

Statement

Analysis of which Red Hat products ship the affected gst-plugins-base RTSP library and/or gst-rtsp-server is still pending component mapping; this statement will be updated once that mapping is complete. The vulnerable code path is only reachable in gst-rtsp-server based RTSP servers when the application has explicitly configured a GstRTSPAuth object (Basic or Digest authentication enabled) -- gst_rtsp_auth_check() short-circuits and never calls the vulnerable parser when no auth object is configured, so RTSP servers/media servers run without authentication are not affected by the server-side attack path. RTSP client code (e.g. rtspsrc, rtspclientsink) that connects to an untrusted/attacker-controlled RTSP server and processes its WWW-Authenticate header is affected regardless of whether the local application itself configures authentication.

Mitigation

No mitigation is currently available that meets Red Hat Product Security's standards for usability, deployment, applicability, 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).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score7.5N/A7.5
Attack VectorNetworkN/ANetwork
Attack ComplexityLowN/ALow
Privileges RequiredNoneN/ANone
User InteractionNoneN/ANone
ScopeUnchangedN/AUnchanged
ConfidentialityNoneN/ANone
Integrity ImpactNoneN/ANone
Availability ImpactHighN/AHigh

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

Red Hat CVSS v3 Score Explanation

Remote, unauthenticated, zero-interaction crash of an RTSP server (or client) process via a single malformed RTSP auth header; no confidentiality/integrity impact, full loss of availability of the affected process.

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Crash, Exit, or Restart

NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.

Integrity,Confidentiality

Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory

In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.

Acknowledgements

Upstream acknowledges Roy Lau (Independent researcher) as the original reporter.

Frequently Asked Questions

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