Quick answers
- Is CVE-2026-35203 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-35203 being exploited in the wild.
- How severe is CVE-2026-35203?
- High severity, with a CVSS score of 7.5, published 6 April 2026.
- Which products and versions are affected?
- Zlmediakit versions up to (excluding) commit 435dcbc.
- Is there a fix for CVE-2026-35203?
- A patch was published on 2026-03-29: Fix commit 435dcbc merged into master Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-35203 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-35203?
- Check whether you run Zlmediakit at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
An out-of-bounds read (CWE-125) exists in the VP9 RTP payload parser within `ext-codec/VP9Rtp.cpp`. The `RTPPayloadVP9::parse` function processes flag bits from the first byte of a payload to determine which optional fields (such as PictureID or Layer Indices) are present. However, it fails to validate the `dataLength` before incrementing the data pointer and dereferencing it. A remote, unauthenticated attacker can send a 1-byte RTP packet with all flag bits set (0xFF), forcing the parser to read multiple bytes past the end of the allocated heap buffer. This can result in a denial of service (segmentation fault) or potential information disclosure if the out-of-bounds data is incorporated into forwarded media frames. The issue is resolved in commit 435dcbcbbf700fd63b2ca9eac6cef3b5ea75169d.
Affected products
- ZLMediaKit ZLMediaKit versions up to (excluding) commit 435dcbc
Timeline
- 2026-04-02: advisory: GitHub Security Advisory published
- 2026-04-06: disclosed: CVE-2026-35203 published
- 2026-03-29: patched: Fix commit 435dcbc merged into master