{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89725","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.759Z","datePublished":"2026-09-11T19:46:36.679Z","dateUpdated":"2026-09-14T12:02:16.023Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-14T12:02:16.023Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: cec: stm32: prevent out-of-bounds write on RX overflow\n\nstm32_rx_done() appends each received CEC byte to rx_msg.msg[] using\nrx_msg.len as the write index, incrementing it on every RXBR\n(receive-byte-ready) interrupt without checking it against the buffer\nsize:\n\n\tcec->rx_msg.msg[cec->rx_msg.len++] = val & 0xFF;\n\nrx_msg.msg[] is a fixed CEC_MAX_MSG_SIZE (16) byte array in struct\ncec_msg, and rx_msg.len is only reset on RXACKE/RXOVR or after a\ncompleted message (RXEND). The number of bytes received before RXEND is\ndecided by the remote CEC device (it sets EOM), not by the driver. A\npeer that keeps sending bytes without ending the message drives RXBR\nrepeatedly, pushing rx_msg.len past 16 and writing peer-controlled bytes\nout of bounds into the surrounding memory. This is reachable in normal\noperation once the driver has probed and receiving is enabled, from the\nIRQ thread, without any local privilege.\n\nThe length check in the CEC core runs on the consumer side, after the\nbyte has been stored, so it does not prevent the overflow. Bound the\nindex in the driver before the store, as the other platform CEC drivers\nalready do (e.g. tegra_cec), dropping the excess bytes of an overlong\nframe.\n\nFound by static analysis tool CodeQL."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - The overflow is in the STM32 HDMI-CEC RX IRQ path (stm32_cec_irq_handler to stm32_cec_irq_thread to stm32_rx_done), driven by bytes a peer places on the shared CEC line. HDMI-CEC is a multi-drop bus among TVs, AVRs, streaming sticks, and conference or automotive HDMI sources, matching CAN/Bluetooth adjacent-segment scoring rather than Internet-routable Network.\nAC:L - A CEC peer fully controls each payload byte and the EOM bit that ends the frame. STM32 hardware raises RXBR per received byte with no 16-byte cap, so withholding EOM at normal CEC bit timing deterministically writes past rx_msg.msg[16] with no race or attacker-uncontrollable layout.\nPR:N - HDMI-CEC has no authentication. Any device on the same CEC bus can emit an overlong frame that the IRQ thread copies into kernel memory; the attacker needs no Linux account, capability, or user-namespace privilege on the STM32 host.\nUI:N - Once the adapter is enabled, which is normal for STM32MP1/STM32F7 HDMI products that claim a CEC logical address at boot, RX interrupts run autonomously. No victim file-open, mount, or prompt is required during the attack.\nS:U - The out-of-bounds write corrupts the kmalloc'd struct stm32_cec and adjacent kernel heap on the same host OS. It does not cross a VM, IOMMU, or other separate security authority.\nC:H - Attacker-controlled bytes are written past the 16-byte rx_msg.msg[] into the rest of the heap object and neighboring slabs. That kernel memory corruption can be leveraged for information disclosure, so Confidentiality is High.\nI:H - This is an unbounded out-of-bounds write of peer-controlled CEC bytes into kernel heap (rx_msg trailing fields, tx_msg, tx_cnt, then adjacent objects), which is an integrity compromise exploitable for arbitrary write or control-flow hijack.\nA:H - Overflowing the CEC RX buffer corrupts kernel heap and slab metadata, causing oops or panic even when not fully exploited for code execution. Heap corruption is scored High availability."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/media/cec/platform/stm32/stm32-cec.c"],"versions":[{"version":"d69ae57453c80a2193bcdb3fd762efbec447eecf","lessThan":"f2499b720ea9b874d58770885c6c2e8445a8c3ef","status":"affected","versionType":"git"},{"version":"d69ae57453c80a2193bcdb3fd762efbec447eecf","lessThan":"3df1a4026662121011187247897fe95fd84e8a3a","status":"affected","versionType":"git"},{"version":"d69ae57453c80a2193bcdb3fd762efbec447eecf","lessThan":"37ac45f7d6e3a6a5dcf6452a0b7bad9a543e8344","status":"affected","versionType":"git"},{"version":"d69ae57453c80a2193bcdb3fd762efbec447eecf","lessThan":"1b4fdefd788db990d1805feb5c7b2388de791ecd","status":"affected","versionType":"git"},{"version":"d69ae57453c80a2193bcdb3fd762efbec447eecf","lessThan":"c3edd7fb8e3692423a702705509947fc9c30b3d1","status":"affected","versionType":"git"},{"version":"d69ae57453c80a2193bcdb3fd762efbec447eecf","lessThan":"0c260d3f97e52978a8c769bb095ac0901333a3ac","status":"affected","versionType":"git"},{"version":"d69ae57453c80a2193bcdb3fd762efbec447eecf","lessThan":"a85ce3b175615c2e13bc01e8a1b6b6b6910fde57","status":"affected","versionType":"git"},{"version":"d69ae57453c80a2193bcdb3fd762efbec447eecf","lessThan":"fb9dda38d4b9e90db07ed9a0ee2d35bf85494035","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/cec/platform/stm32/stm32-cec.c"],"versions":[{"version":"4.13","status":"affected"},{"version":"0","lessThan":"4.13","status":"unaffected","versionType":"semver"},{"version":"5.10.270","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.221","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.188","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.157","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.109","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.50","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.4","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","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":"4.13","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"7.3-rc1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/f2499b720ea9b874d58770885c6c2e8445a8c3ef"},{"url":"https://git.kernel.org/stable/c/3df1a4026662121011187247897fe95fd84e8a3a"},{"url":"https://git.kernel.org/stable/c/37ac45f7d6e3a6a5dcf6452a0b7bad9a543e8344"},{"url":"https://git.kernel.org/stable/c/1b4fdefd788db990d1805feb5c7b2388de791ecd"},{"url":"https://git.kernel.org/stable/c/c3edd7fb8e3692423a702705509947fc9c30b3d1"},{"url":"https://git.kernel.org/stable/c/0c260d3f97e52978a8c769bb095ac0901333a3ac"},{"url":"https://git.kernel.org/stable/c/a85ce3b175615c2e13bc01e8a1b6b6b6910fde57"},{"url":"https://git.kernel.org/stable/c/fb9dda38d4b9e90db07ed9a0ee2d35bf85494035"}],"title":"media: cec: stm32: prevent out-of-bounds write on RX overflow","x_generator":{"engine":"bippy-1.2.0"}}}}