CVE-2026-30754: Memory Corruption (CVSS 8.8)

Description

A memory corruption vulnerability exists in FFmpeg before 8.1. The RTP encoding process. In the nal_send function in libavformat/rtpenc_h264_hevc.c, a negative size parameter (size=-3) is passed to memcpy when transmitting H.264/HEVC streams via RTP using a crafted input file. This was detected using AddressSanitizer.

Is your site exposed to CVE-2026-30754?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0035

Probability of exploitation

0.28%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

References

Other References

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20746 https://gist.github.com/momo-trip/4cddf2c9e15600873de55259dac6b0e6 https://github.com/momo-trip/poc_ffmpeg

Frequently Asked Questions

What is CVE-2026-30754? +

A memory corruption vulnerability exists in FFmpeg before 8.1. The RTP encoding process. In the nal_send function in libavformat/rtpenc_h264_hevc.c, a negative size parameter (size=-3) is passed to memcpy when transmitting H.264/HEVC streams via RTP using a crafted input file. This was detected using AddressSanitizer. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-30754? +

CVE-2026-30754 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0035, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-30754? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-8358

LibreOffice Calc can import tracked changes from a spreadsheet document. A heap buffer overflow existed when a document reused the …

CVE-2026-8356

LibreOffice can import presentations in the legacy binary PPT format. A stack buffer overflow existed when importing a colour-replacement record. …

CVE-2026-6040

A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the …

CVE-2026-6039

LibreOffice can import drawings in the DXF format used by CAD software. A heap buffer overflow existed when importing a …

CVE-2026-3298

The method "sock_recvfrom_into()" of "asyncio.ProacterEventLoop" (Windows only) was missing a boundary check for the data buffer when using nbytes parameter. …

CVE-2026-14297

A buffer overflow in the Bluetooth Continuous Glucose Monitoring Service (CGMS) Record Access Control Point (RACP) write handler allows an …

CVE-2026-30754