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Kvazaar through 2.3.2 Infinite Loop DoS via Y4M Header Parser

Kvazaar through 2.3.2's command-line encoder hangs when reading a Y4M file whose header lacks a trailing newline before end of file. No fixed version is listed in the checked facts.

Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.

6.8MediumCNA
Exploited
No known exploitation
Fix
Fix or patch referenced
Who is exposed
Specific setups only

Do first: Check whether your setup matches what the bug needs. Affects Kvazaar through 2.3.2 (command-line encoder read_header path); the report tested v2.3.2 and older tags v2.1.0 and v2.2.0. Input must be a .y4m file (auto format detected by extension) or an explicit y4m input format. The Y4M header must end without a newline before end of file (truncated header).

Published
Last modified
Published
Not listed in CISA KEV
12/100 · provisional
Specific setups only
Fix
Fix or patch referenced
None on Exploit-DB, Metasploit or GitHub

Summary

Kvazaar through 2.3.2 contains an infinite loop vulnerability in read_header() in src/encmain.c that allows attackers to hang the command-line encoder by supplying a truncated Y4M header. Attackers can provide a crafted .y4m file lacking a terminating newline, causing unchecked EOF reads that hang the process indefinitely while consuming a full CPU core.

What to do

  • Check whether your setup matches what the bug needs.

    Affects Kvazaar through 2.3.2 (command-line encoder read_header path); the report tested v2.3.2 and older tags v2.1.0 and v2.2.0. Input must be a .y4m file (auto format detected by extension) or an explicit y4m input format. The Y4M header must end without a newline before end of file (truncated header).
  • Apply the patch listed under Evidence.

Timeline

  1. CVE published
  2. First seen by cve.now

Affected versions

  • Ultra Video Group Kvazaar

    through 2.3.2

Evidence 6

  1. Patch
  2. Report
  3. Repository
  4. Repository
  5. Link
  6. Link

Corrections

None so far.

Something wrong on this page? Report an error. Every fix is listed here.

FAQ

Questions about CVE-2026-120458

What does this mean?

A Y4M video file whose header is cut off with no newline before the end of the file can make the kvazaar encoder hang inside its header reader. The process then uses a full CPU core and never produces output or exits until it is killed.Source: github.com

Am I affected, and how do I check?

Kvazaar through 2.3.2 is listed, and the report tested v2.3.2 plus the older tags v2.1.0 and v2.2.0. The relevant setup is the command-line encoder reading .y4m input, detected either by the .y4m file extension or an explicit y4m input format. Checking the installed kvazaar version against 2.3.2 shows whether a given install falls in the listed range.Source: github.com

What should I do about it?

The checked facts record no fixed release, so no upgrade target can be given yet. Until a fixed version is published, avoid passing untrusted .y4m files to the kvazaar encoder.Source: github.com

Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data