{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68206", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.374Z", "datePublished": "2026-08-10T12:00:25.309Z", "dateUpdated": "2026-08-19T16:31:26.837Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:31:26.837Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: v4l2-ctrls: validate HEVC active reference counts\n\nHEVC slice parameters are shared stateless V4L2 controls, but the common\nvalidation path does not verify the active L0/L1 reference counts before\ndriver-specific code consumes them.\n\nThe original report came from Cedrus, but the active count bounds are\nnot Cedrus-specific. Validate them in the common HEVC slice control path\nso stateless HEVC drivers get the same basic guarantees as soon as the\ncontrol is queued.\n\nDo not reject ref_idx_l0/ref_idx_l1 entries here. Existing userspace may\nuse out-of-range sentinel values such as 0xff for missing references, and\nsome hardware can use that information for concealment. Keep this common\ncheck limited to the active reference counts." } ], "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 control is only settable through VIDIOC_S_EXT_CTRLS on the local V4L2 stateless decoder node (/dev/videoN), followed by QBUF/STREAMON on the same fd. There is no network or remote path into the HEVC slice-params control.\nAC:L - The attacker supplies num_ref_idx_l0/l1_active_minus1 verbatim as a u8; any value in 16..254 deterministically drives the loops in cedrus_h265_is_low_delay() and rkvdec_hevc set_ps_field() out of bounds on the very next decode run. No race, timing window, or uncontrollable memory layout is involved.\nPR:L - Only an unprivileged local account holding the video device node is required (typically the 'video' group, or the media/codec service reachable from sandboxed apps on Android and embedded Allwinner/Rockchip devices). cedrus_try_ctrl() checks only SPS chroma format and bit depth; no capability or root check exists on the path.\nUI:N - The attacking process performs the whole sequence itself: open the decoder, set the crafted HEVC slice-params control, queue buffers and start streaming. No victim action, media file, or mount is needed.\nS:U - The out-of-bounds accesses stay inside the kernel's own slab and DMA memory within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - decode_params->dpb[] holds 16 16-byte entries at the tail of a ~336-byte control allocation, so an index up to 255 reads roughly 3.8 KB of adjacent kernel heap; the pred-weight loops likewise read 240 bytes past slice_params. Those OOB bytes are fed into decoder SRAM and steer the low-delay decision, giving an attacker-steerable oracle over unrelated kernel memory.\nI:H - In rkvdec-hevc, REF_PIC_IDX_L0(i)/REF_PIC_LONG_TERM_L1(i) with i up to 255 resolve to bit offset ~1276 in an 8-word rkvdec_rps_packet, so set_ps_field() performs an out-of-bounds write of attacker-chosen bits at an attacker-chosen offset into (and past the end of) the coherent DMA priv_tbl, corrupting hardware descriptor state and adjacent memory.\nA:H - Reading several kilobytes past a slab object can walk into an unmapped or poisoned region and trips KASAN/hardening checks, while the rkvdec out-of-bounds write corrupts the DMA table handed to the decoder; either yields a kernel oops or wedged hardware, repeatable at will from an unprivileged process." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/media/v4l2-core/v4l2-ctrls-core.c" ], "versions": [ { "version": "d395a78db9eabd12633b39e05c80e803543b6590", "lessThan": "3299c3905f3fb439ebd892658b87bc76c93ae116", "status": "affected", "versionType": "git" }, { "version": "d395a78db9eabd12633b39e05c80e803543b6590", "lessThan": "9a998cc1c348769262d433acb7d238c5fac4b2e0", "status": "affected", "versionType": "git" }, { "version": "d395a78db9eabd12633b39e05c80e803543b6590", "lessThan": "dbaf0e0023e2f9332c5164822def7f80b7d2c5ef", "status": "affected", "versionType": "git" }, { "version": "d395a78db9eabd12633b39e05c80e803543b6590", "lessThan": "3068ab802fc98b121dcb451e1f7f4d338ffc7a19", "status": "affected", "versionType": "git" }, { "version": "d395a78db9eabd12633b39e05c80e803543b6590", "lessThan": "b01df98a6669d2b67d8aed816021b327fd905998", "status": "affected", "versionType": "git" }, { "version": "d395a78db9eabd12633b39e05c80e803543b6590", "lessThan": "afbe4bc252d90a6f8fad869b06d5430f615f22f9", "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/media/v4l2-core/v4l2-ctrls-core.c" ], "versions": [ { "version": "5.14", "status": "affected" }, { "version": "0", "lessThan": "5.14", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "5.14", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.6.148" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.12.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3299c3905f3fb439ebd892658b87bc76c93ae116" }, { "url": "https://git.kernel.org/stable/c/9a998cc1c348769262d433acb7d238c5fac4b2e0" }, { "url": "https://git.kernel.org/stable/c/dbaf0e0023e2f9332c5164822def7f80b7d2c5ef" }, { "url": "https://git.kernel.org/stable/c/3068ab802fc98b121dcb451e1f7f4d338ffc7a19" }, { "url": "https://git.kernel.org/stable/c/b01df98a6669d2b67d8aed816021b327fd905998" }, { "url": "https://git.kernel.org/stable/c/afbe4bc252d90a6f8fad869b06d5430f615f22f9" } ], "title": "media: v4l2-ctrls: validate HEVC active reference counts", "x_generator": { "engine": "bippy-1.2.0" } } } }