FFmpeg through 9.0.2 Uninitialized Memory Disclosure via JPEG-LS Decoder
- Exploited
- No known exploitation
- Fix
- Fix or patch referenced
- Who is exposed
- Not reported
Do first: Apply the patch listed under Evidence.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 5/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
FFmpeg through version 9.0.2 is affected, and the bug is local but needs no login; it requires the user to open a crafted JPEG-LS image, which causes decoded 16-bit grayscale frames to leak leftover heap memory contents. The attacker gains read access to some memory information, not code execution or modification of data.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
FFmpeg through 9.0.2 contains an uninitialized memory disclosure vulnerability in ff_jpegls_decode_picture() in libavcodec/jpeglsdec.c, which decodes 16-bit line-interleaved JPEG-LS scans as 8-bit samples. Attackers can supply a crafted single-component JPEG-LS image with the ILV byte set to 1, causing decoded GRAY16 frames to expose leftover heap memory.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure?/25Unknown. No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity4.8/10CVSS 4.8
- No patch0/5No signal
What would change the score
- Would score about 60 if added to CISA KEV
- Would score about 55 if CISA's SSVC rates exploitation active
- Would score about 27 if advisories confirm default setups are exposed
What to do
Apply the patch listed under Evidence.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- FFmpeg FFmpeg
through 9.0.2
Evidence 5
- Patch
- Report
- Repository
- Repository
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-125243
Is CVE-2026-125243 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
Which versions are affected by CVE-2026-125243?
FFmpeg: through 9.0.2.Source: cve.now feed data