CVE-2026-66038

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Source
https://cve.org/CVERecord?id=CVE-2026-66038
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66038.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-66038
Downstream
Related
Published
2026-07-24T19:39:27.448Z
Modified
2026-08-12T03:51:20.242157495Z
Severity
  • 7.1 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
FFmpeg LCL/ZLIB Video Decoder Information Disclosure via lcldec.c
Details

FFmpeg through 8.1.2, fixed in commit 8670835, contains an information disclosure vulnerability in the LCL/ZLIB video decoder that allows attackers to expose uninitialized heap memory by supplying a valid zlib stream that inflates to fewer bytes than the expected frame size. The zlib_decomp() function in lcldec.c treats short decompression as non-fatal and continues to the RGB24 conversion path, which copies a full frame's worth of rows from the allocation buffer using original frame dimensions, causing uninitialized heap contents including pointer-derived allocator bytes to be copied into the attacker-observable AVFrame output and potentially defeating ASLR in long-lived media processing services.

Database specific 
{
    "cwe_ids": [
        "CWE-908"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66038.json",
    "cna_assigner": "VulnCheck",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "last_affected": "8.1.2"
                }
            ],
            "source": "AFFECTED_FIELD"
        },
        {
            "extracted_events": [
                {
                    "last_affected": "8.1.2"
                }
            ],
            "source": "CPE_FIELD"
        },
        {
            "extracted_events": [
                {
                    "fixed": "8.1.2"
                }
            ],
            "source": "DESCRIPTION"
        }
    ]
}
References

Affected packages

Git / github.com/ffmpeg/ffmpeg

Affected ranges

Type
GIT
Repo
https://github.com/ffmpeg/ffmpeg
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Last affected
38b88335f99e76ed89ff3c93f877fdefce736c13
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:ffmpeg:ffmpeg:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "last_affected": "8.1.2"
        }
    ],
    "source": "CPE_RANGE"
}

Affected versions

Other
N
n0.*
n0.11-dev
n0.12-dev
n0.8
n1.*
n1.1-dev
n1.2-dev
n1.3-dev
n2.*
n2.0
n2.1-dev
n2.2-dev
n2.3-dev
n2.4-dev
n2.5-dev
n2.6-dev
n2.7-dev
n2.8-dev
n2.9-dev
n3.*
n3.1-dev
n3.2-dev
n3.3-dev
n3.4-dev
n3.5-dev
n4.*
n4.1-dev
n4.2-dev
n4.3-dev
n4.4-dev
n4.5-dev
n5.*
n5.1-dev
n5.2-dev
n6.*
n6.1-dev
n6.2-dev
n7.*
n7.1-dev
n7.2-dev
n8.*
n8.1
n8.1-dev
n8.1.1
n8.1.2

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66038.json"