CVE-2025-27091
Cisco OpenH264 Heap Overflow Vulnerability
Description
OpenH264 is a free license codec library which supports H.264 encoding and decoding. A vulnerability in the decoding functions of OpenH264 codec library could allow a remote, unauthenticated attacker to trigger a heap overflow. This vulnerability is due to a race condition between a Sequence Parameter Set (SPS) memory allocation and a subsequent non Instantaneous Decoder Refresh (non-IDR) Network Abstraction Layer (NAL) unit memory usage. An attacker could exploit this vulnerability by crafting a malicious bitstream and tricking a victim user into processing an arbitrary video containing the malicious bistream. An exploit could allow the attacker to cause an unexpected crash in the victim's user decoding client and, possibly, perform arbitrary commands on the victim's host by abusing the heap overflow. This vulnerability affects OpenH264 2.5.0 and earlier releases. Both Scalable Video Coding (SVC) mode and Advanced Video Coding (AVC) mode are affected by this vulnerability. OpenH264 software releases 2.6.0 and later contained the fix for this vulnerability. Users are advised to upgrade. There are no known workarounds for this vulnerability. ### For more information If you have any questions or comments about this advisory: * [Open an issue in cisco/openh264](https://github.com/cisco/openh264/issues) * Email Cisco Open Source Security ([[email protected]](mailto:[email protected])) and Cisco PSIRT ([[email protected]](mailto:[email protected])) ### Credits: * **Research:** Octavian Guzu and Andrew Calvano of Meta * **Fix ideation:** Philipp Hancke and Shyam Sadhwani of Meta * **Fix implementation:** Benzheng Zhang (@BenzhengZhang) * **Release engineering:** Benzheng Zhang (@BenzhengZhang)
INFO
Published Date :
Feb. 20, 2025, 6:15 p.m.
Last Modified :
Feb. 27, 2025, 8:18 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
5.9
Exploitability Score :
1.6
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-27091
.
URL | Resource |
---|---|
https://github.com/cisco/openh264/releases/tag/v2.6.0 | Release Notes |
https://github.com/cisco/openh264/security/advisories/GHSA-m99q-5j7x-7m9x | Vendor Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-27091
vulnerability anywhere in the article.

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Cybersecurity News
OpenH264 Codec Vulnerability (CVE-2025-27091): Remote Code Execution Possible
Cisco has released a security advisory concerning a high-severity vulnerability in the OpenH264 codec library. Tracked as CVE-2025-27091 and assigned a CVSSv4 score of 8.6, this vulnerability could al ... Read more
The following table lists the changes that have been made to the
CVE-2025-27091
vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 27, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-787 Added CPE Configuration OR *cpe:2.3:a:cisco:openh264:*:*:*:*:*:*:*:* versions from (excluding) 2.6.0 Added Reference Type GitHub, Inc.: https://github.com/cisco/openh264/releases/tag/v2.6.0 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/cisco/openh264/security/advisories/GHSA-m99q-5j7x-7m9x Types: Vendor Advisory -
New CVE Received by [email protected]
Feb. 20, 2025
Action Type Old Value New Value Added Description OpenH264 is a free license codec library which supports H.264 encoding and decoding. A vulnerability in the decoding functions of OpenH264 codec library could allow a remote, unauthenticated attacker to trigger a heap overflow. This vulnerability is due to a race condition between a Sequence Parameter Set (SPS) memory allocation and a subsequent non Instantaneous Decoder Refresh (non-IDR) Network Abstraction Layer (NAL) unit memory usage. An attacker could exploit this vulnerability by crafting a malicious bitstream and tricking a victim user into processing an arbitrary video containing the malicious bistream. An exploit could allow the attacker to cause an unexpected crash in the victim's user decoding client and, possibly, perform arbitrary commands on the victim's host by abusing the heap overflow. This vulnerability affects OpenH264 2.5.0 and earlier releases. Both Scalable Video Coding (SVC) mode and Advanced Video Coding (AVC) mode are affected by this vulnerability. OpenH264 software releases 2.6.0 and later contained the fix for this vulnerability. Users are advised to upgrade. There are no known workarounds for this vulnerability. ### For more information If you have any questions or comments about this advisory: * [Open an issue in cisco/openh264](https://github.com/cisco/openh264/issues) * Email Cisco Open Source Security ([[email protected]](mailto:[email protected])) and Cisco PSIRT ([[email protected]](mailto:[email protected])) ### Credits: * **Research:** Octavian Guzu and Andrew Calvano of Meta * **Fix ideation:** Philipp Hancke and Shyam Sadhwani of Meta * **Fix implementation:** Benzheng Zhang (@BenzhengZhang) * **Release engineering:** Benzheng Zhang (@BenzhengZhang) Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-122 Added Reference https://github.com/cisco/openh264/releases/tag/v2.6.0 Added Reference https://github.com/cisco/openh264/security/advisories/GHSA-m99q-5j7x-7m9x
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-27091
is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-27091
weaknesses.