FFmpeg 3.0 < 9.0 Uninitialized Heap Memory Read in Screenpresso Decoder
Summary
| CVE | CVE-2026-70630 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-06 22:18:27 UTC |
| Updated | 2026-08-07 18:17:22 UTC |
| Description | FFmpeg versions from 3.0 up to, but not including, 9.0 contain an uninitialized heap memory read vulnerability in the native Screenpresso decoder (libavcodec/screenpresso.c) that allows attackers to recover sensitive memory contents by supplying a crafted SPV1 packet with a valid zlib stream that decompresses fewer bytes than the full frame requires. The screenpresso_decode_frame() function fails to validate the produced byte count before calling av_image_copy_plane() to copy the complete frame dimensions from the persistent ctx->inflated_buf buffer, causing unwritten heap memory from prior allocations or prior frames to be copied into decoded output and potentially exposing sensitive data such as userspace addresses from persistent decoding services. |
Risk And Classification
Primary CVSS: v4.0 6.8 MEDIUM from [email protected]
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
EPSS: 0.001320000 probability, percentile 0.031820000 (date 2026-08-10)
Problem Types: CWE-908 | CWE-908 Use of Uninitialized Resource
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.8 | MEDIUM | 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/C... |
| 4.0 | CNA | CVSS | 6.8 | MEDIUM | 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 |
| 3.1 | [email protected] | Secondary | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| 3.1 | CNA | CVSS | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
CVSS v4.0 Breakdown
Attack Vector
LocalAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
PassiveConfidentiality
HighIntegrity
NoneAvailability
NoneSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
NoneAvailability
NoneCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| code.ffmpeg.org/FFmpeg/FFmpeg/commit/705890061467ad550ecc1dad5eea07f28ccfb43e | [email protected] | code.ffmpeg.org | |
| code.ffmpeg.org/FFmpeg/FFmpeg/commit/c22667d0fd7916a33fd3e79685b7246fc48f1a62 | [email protected] | code.ffmpeg.org | |
| www.vulncheck.com/advisories/ffmpeg-uninitialized-heap-memory-read-in-screenpre... | [email protected] | www.vulncheck.com | |
| code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23896 | [email protected] | code.ffmpeg.org | |
| code.ffmpeg.org/FFmpeg/FFmpeg/commit/9a3202a98b2e095b54dd784c3e01a09a676fc3fa | [email protected] | code.ffmpeg.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Adrian Junge (vurlo) (en)
There are currently no legacy QID mappings associated with this CVE.