{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63849","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-19T07:54:57.016Z","datePublished":"2026-07-19T14:04:41.395Z","dateUpdated":"2026-08-05T12:36:27.366Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:36:27.366Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/vcn: set no_user_fence for VCN v5.0.1 enc ring\n\nVCN encoder and decoder rings do not support 64-bit user fence writes,\nreject CS submissions with user fences.\n\n(cherry picked from commit e16be95a2c3ee712b142cb27d2dca0b461181359)"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerability is reached only through local DRM ioctls (primarily DRM_IOCTL_AMDGPU_CS on a /dev/dri/renderD* node), not over any network protocol.\nAC:L - An attacker with render-node access can deterministically submit a VCN_ENC command buffer with an AMDGPU_CHUNK_ID_FENCE chunk; no race or attacker-uncontrollable conditions are required beyond having the affected AMDGPU hardware.\nPR:L - Exploitation requires only local access to the GPU render node as an unprivileged user (DRM_AUTH|DRM_RENDER_ALLOW); no root or special capabilities are needed.\nUI:N - Triggering the bug requires only the attacker's own ioctl submissions; no action by another user or victim is required.\nS:U - Impact is confined to the attacker's GPU command-submission context and process GPU virtual address space; it does not cross a VM/host or other security-boundary scope.\nC:H - The unsupported 64-bit user-fence path causes the VCN engine to perform GPU memory writes to attacker-influenced addresses, which constitutes exploitable memory corruption that can be leveraged for information disclosure.\nI:H - The malformed fence write gives the attacker a GPU-initiated arbitrary memory write primitive within their GPU VA space, which can corrupt adjacent buffers and be chained toward code execution.\nA:H - Submitting unsupported user fences to the VCN ring can hang or reset the GPU and trigger kernel driver errors, causing denial of service on affected systems."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c"],"versions":[{"version":"346492f30ce3581bf5324c4ae417eab8537dc998","lessThan":"081ef0e46c9cdd26c0db0ef721470393d36b6655","status":"affected","versionType":"git"},{"version":"346492f30ce3581bf5324c4ae417eab8537dc998","lessThan":"5a4bffd67e94944ed3db26a959346cfb7fabaecd","status":"affected","versionType":"git"},{"version":"346492f30ce3581bf5324c4ae417eab8537dc998","lessThan":"8f4954722eab88e10c4ea0c0d3b1269c31421d3a","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/amdgpu/vcn_v5_0_1.c"],"versions":[{"version":"6.14","status":"affected"},{"version":"0","lessThan":"6.14","status":"unaffected","versionType":"semver"},{"version":"6.18.33","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.10","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/081ef0e46c9cdd26c0db0ef721470393d36b6655"},{"url":"https://git.kernel.org/stable/c/5a4bffd67e94944ed3db26a959346cfb7fabaecd"},{"url":"https://git.kernel.org/stable/c/8f4954722eab88e10c4ea0c0d3b1269c31421d3a"}],"title":"drm/amdgpu/vcn: set no_user_fence for VCN v5.0.1 enc ring","x_generator":{"engine":"bippy-1.2.0"}}}}