CVE-2026-35203Public exploitNetwork attack vector

Server crash via unchecked VP9 descriptor reads

Published Apr 6, 2026 · Updated Apr 6, 2026

Out-of-bounds read in ZLMediaKit allows remote attackers to crash MediaServer by sending crafted VP9 RTP packets. The RTPPayloadVP9::parse() function trusts descriptor flags in the first payload byte and dereferences optional fields without checking dataPtr against the payload length. Reachability requires a deployment that accepts attacker-supplied VP9 streams over RTSP, WebRTC, or RTP proxy, and the established consequence is a server crash.

CVSS severity7.5
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in ZLMediaKit allows remote attackers to crash MediaServer by sending crafted VP9 RTP packets. The RTPPayloadVP9::parse() function trusts descriptor flags in the first payload byte and dereferences optional fields without checking dataPtr against the payload length. Reachability requires a deployment that accepts attacker-supplied VP9 streams over RTSP, WebRTC, or RTP proxy, and the established consequence is a server crash.

The record

CVE
CVE-2026-35203
Published
Apr 6, 2026
Updated
Apr 6, 2026
Vendor
ZLMediaKit
Product
ZLMediaKit
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 435dcbcbbf700fd63b2ca9eac6cef3b5ea75169d

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ZLMediaKit · ZLMediaKitversion=< 435dcbcbbf700fd63b2ca9eac6cef3b5ea75169d

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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