CVE-2026-59692
Description
A stack buffer overflow vulnerability was found in GStreamer's DTLS plugin. During a DTLS handshake, the peer certificate Subject Distinguished Name is printed into a fixed-size 2048-byte stack buffer without bounds checking. A remote unauthenticated attacker can send a certificate with an oversized Subject DN that exceeds the buffer, causing a stack buffer overflow and process crash, resulting in denial of service.
Statement
This vulnerability is rated as Important severity because it is remotely triggerable without authentication or user interaction during a DTLS handshake. However, the actual impact is limited to denial of service. Remote code execution is not achievable because X509_NAME_print_ex() escapes all binary and control characters to printable ASCII sequences, preventing arbitrary byte injection into the overflow. Combined with stack canary protection (-fstack-protector-strong) in Red Hat builds, return address corruption cannot be exploited. The DTLS plugin is shipped as part of gstreamer1-plugins-bad-free in Red Hat Enterprise Linux 8, 9, 10, and RHIVOS. It is used by GStreamer WebRTC pipelines.
Mitigation
There is no complete mitigation for this vulnerability. The following measures can reduce risk:
1. If WebRTC/DTLS functionality is not required, remove the DTLS plugin shared object from the GStreamer plugins directory (typically /usr/lib64/gstreamer-1.0/libgstdtls.so).
2. Restrict network access to WebRTC/DTLS endpoints to trusted peers only via firewall rules.
3. Deploy GStreamer WebRTC services behind a reverse proxy or media server that validates DTLS certificates before forwarding.
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 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
Red Hat CVSS v3 Score Explanation
AV:N - DTLS handshake is network-accessible. AC:L - straightforward to trigger with crafted certificate. PR:N - no authentication required, just initiate DTLS handshake. UI:N - server processes certificate automatically during handshake. S:U - stays within GStreamer process. C:N - text-only overflow cannot read memory. I:N - text-only overflow content (escaped printable ASCII) cannot modify meaningful data for exploitation. A:H - reliable crash via stack canary abort.
Understanding the Weakness (CWE)
Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
Integrity,Confidentiality,Availability,Access Control
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands; Bypass Protection Mechanism
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy.
Integrity,Confidentiality,Availability,Access Control,Other
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Other
When the consequence is arbitrary code execution, this can often be used to subvert any other security service.
Acknowledgements
Red Hat would like to thank Clouditera Security (Clouditera), NSFOCUS (NSFOCUS), and Z.ai Security (Z.ai) for reporting this issue.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
