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🛡️ JLSEC-2026-1191 — ffmpeg-jll (CVE-2026-70631)

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

FFmpeg versions from 0.5 up to, but not including, 9.0 contain an uninitialized heap memory...

FFmpeg versions from 0.5 up to, but not including, 9.0 contain an uninitialized heap memory disclosure vulnerability in the native TIFF decoder in libavcodec/tiff.c. An attacker who can cause FFmpeg to decode a crafted TIFF file can supply a valid Deflate-compressed strip that terminates successfully after producing fewer bytes than the declared strip requires. The tiff_unpack_zlib() function allocates a heap buffer sized for the full declared strip but copies all declared rows via memcpy() regardless of how many bytes zlib actually decompressed, causing unwritten bytes that can contain stale data from prior heap allocations to be incorporated into decoded image output and potentially exposing sensitive data in persistent services.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity none, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/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

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Attack requirements: None — no deployment-specific condition has to hold.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: Passive — a victim action is involved, but not a deliberate one.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: None.
  • Availability impact: None.

Affected software

JLSEC-2026-1191 is recorded against 3 packages.

  • ffmpeg-jll
  • ffmpeg-nogpl-jll
  • ffplay-jll

Timeline and source

Published on 7 August 2026 and last revised on 8 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

code.ffmpeg.org (Web)
code.ffmpeg.org (Web)
code.ffmpeg.org (Web)
code.ffmpeg.org (Web)
github.com (Web)
nvd.nist.gov (Web)
www.vulncheck.com (Web)

Other advisories for this package

ffmpeg-jll has other advisories on record. If you are patching this one, these are worth checking on the same host:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/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
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-08-07
Updated 2026-08-20
Modified 2026-08-08
Fix URL N/A

Affected Packages

Software From version Fixed in
ffmpeg-jll — —
ffmpeg-nogpl-jll — —
ffplay-jll — —

Similar Threats

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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