# CVE-2026-125066: FFmpeg through 9.0.2 NULL Pointer Dereference in CLJR Video Decoder

Status: published. Published: 2026-11-09. Updated: 2026-11-09.

FFmpeg through 9.0.2 contains a NULL pointer dereference vulnerability in the Cirrus Logic AccuPak (CLJR) decoder in libavcodec/cljrdec.c because decode_frame() ignores init_get_bits() failure. Attackers can supply a crafted AVI file with a 2^28-byte CLJR frame that overflows the bit count, causing reads from a NULL buffer and crashing the process.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/FFmpeg/FFmpeg/commit/d40c1b12811814fc6c2d0816527b003d8510ea06

## Affected products and versions

- FFmpeg / FFmpeg (ffmpeg/ffmpeg): ≥ 0; ≤ 9.0.2 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 6.8 (medium); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 5.5 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H; source: CNA: VulnCheck

- CVSS 4.0: 6.8 (medium); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 5.5 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-252

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25704 (CNA: VulnCheck; issue-tracking)

- https://github.com/FFmpeg/FFmpeg/commit/d40c1b12811814fc6c2d0816527b003d8510ea06 (CNA: VulnCheck; patch)

- https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/cljrdec.c#L54 (CNA: VulnCheck; technical-description)

- https://github.com/FFmpeg/FFmpeg (CNA: VulnCheck; product)

- https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-null-pointer-dereference-in-cljr-video-decoder (CNA: VulnCheck; third-party-advisory)

- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25704 (disclosure@vulncheck.com)

- https://github.com/FFmpeg/FFmpeg (disclosure@vulncheck.com)

- https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/cljrdec.c#L54 (disclosure@vulncheck.com)

- https://github.com/FFmpeg/FFmpeg/commit/d40c1b12811814fc6c2d0816527b003d8510ea06 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-null-pointer-dereference-in-cljr-video-decoder (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-125066; retrieved 2026-11-09; source updated 2026-11-09

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-125066; retrieved 2026-11-10; source updated 2026-11-09

Revision: de9864f243425353fa2d054eb8e92f8ac8001807efe9922b3c7258a3707fe6c9

Canonical: https://y2.dev/cve/CVE-2026-125066

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.