CVE-2026-66038

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{"bugzilla": {"description": "FFmpeg: Information disclosure via malformed zlib video stream", "id": "2506938", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2506938"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N", "status": "draft"}, "cwe": "CWE-908", "details": ["A flaw was found in FFmpeg, specifically within the LCL/ZLIB video decoder. A remote attacker could exploit this vulnerability by providing a specially crafted zlib stream that decompresses to a smaller size than expected. This can lead to the exposure of uninitialized heap memory, including sensitive data, which an attacker could observe in the AVFrame output. This information disclosure could potentially aid in bypassing Address Space Layout Randomization (ASLR) in long-running media processing services."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, services utilizing FFmpeg for LCL/ZLIB video stream decoding should avoid returning raw, decoded frame data to untrusted external endpoints. Implement robust input validation for all video streams processed by such services. Additionally, consider sandboxing FFmpeg processes that handle untrusted video content to limit potential information exposure."}, "name": "CVE-2026-66038", "package_state": [{"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "ffmpeg", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-aws-cuda-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-azure-cuda-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-azure-rocm-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-cuda-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-gcp-cuda-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:enterprise_linux_ai:3", "fix_state": "Affected", "package_name": "rhelai3/bootc-rocm-rhel9", "product_name": "Red Hat Enterprise Linux AI (RHEL AI) 3"}, {"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Affected", "package_name": "rhoai/odh-vllm-gaudi-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}], "public_date": "2026-07-24T19:39:27Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-66038\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-66038\nhttps://code.ffmpeg.org/FFmpeg/FFmpeg/commit/e7cbfd1c507b57a806a5825b87d609963e862c8c\nhttps://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23626\nhttps://www.vulncheck.com/advisories/ffmpeg-lcl-zlib-video-decoder-information-disclosure-via-lcldec-c"], "statement": "Our assessment reflects that this flaw strictly impacts Confidentiality with zero effect on Integrity or Availability (I:N, A:N). It cannot be exploited to crash services, corrupt heap memory, or execute arbitrary code. \nFor an exposure to occur, an attacker must supply a truncated LCL/ZLIB video stream to a service that not only decodes the frame, but explicitly encodes and outputs or streams that rendered frame back to an attacker-observable endpoint. In practice, uninitialized heap bytes (which may include allocator pointer addresses) are copied into the output frame buffer; however, reading these bytes requires an active, two-way media channel. \nSystems or pipelines that process video content headlessly or internally (such as background media indexing, thumbnail extraction without public exposure, or one-way ingest) do not expose uninitialized memory to external observers and are not at risk of information leakage from this flaw.", "threat_severity": "Moderate"}

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