CVE-2026-35203 ZLMediaKit VP9 RTP Parser Out-of-Bounds Read

High 7.5 Published Updated

A crafted VP9 RTP packet causes a heap-buffer-overflow in ZLMediaKit, potentially leading to denial of service or code execution.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-35203?

CVE-2026-35203 is a high-severity memory corruption vulnerability in ZLMediaKit, published on 6 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

ZLMediaKit is a streaming media service framework. the VP9 RTP payload parser in ext-codec/VP9Rtp.cpp reads multiple fields from the RTP payload based on flag bits in the first byte, without verifying that sufficient data exists in the buffer. A crafted VP9 RTP packet with a 1-byte payload (0xFF, all flags set) causes the parser to read past the end of the allocated buffer, resulting in a heap-buffer-overflow. This vulnerability is fixed with commit 435dcbcbbf700fd63b2ca9eac6cef3b5ea75169d.

Weakness: CWE-125

Which versions are affected by CVE-2026-35203?

It affects 1 product.

Products include Zlmediakit Zlmediakit.

How do I fix CVE-2026-35203?

No fix has been published for CVE-2026-35203 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-35203 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35203 exists.

Sources

Also known as GHSA-gxr3-fwc7-q99h.

Is CVE-2026-35203 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free