{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74687", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.926Z", "datePublished": "2026-08-22T15:32:52.792Z", "dateUpdated": "2026-08-25T05:41:31.491Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:41:31.491Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwatchdog: at91sam9_wdt: prevent timer rearm during teardown\n\nat91_ping() rearms the watchdog timer from its callback. timer_delete()\nneither waits for a running callback nor prevents it from rearming the\ntimer, so probe failure or driver removal can leave the timer accessing the\ndevm-allocated at91wdt after it has been freed.\n\nUse timer_shutdown_sync() on both teardown paths. It waits for a running\ncallback and rejects any attempt by the callback to rearm the timer."}], "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 bug is in the AT91SAM9 platform watchdog driver during probe-failure cleanup or driver removal; it is reached only via local kernel/platform actions (boot probe, module load/unload, sysfs bind/unbind), not from network, Bluetooth, or physical USB/serial input paths.\nAC:L - at91_ping() unconditionally re-arms with mod_timer() while timer_delete() neither waits for the callback nor blocks rearm; an attacker who can time teardown or trigger the automatic probe-failure path can reliably race the periodic jiffies callback without uncontrollable layout or victim state.\nPR:L - Per CNA driver timer-teardown UAF precedent, once mod_timer() arms at91_ping() the callback runs autonomously; the UAF is reachable from local probe-failure cleanup or driver-removal activity on AT91 embedded/industrial targets without requiring init-namespace root privileges.\nUI:N - No victim interaction is required; the kernel timer fires on its own schedule and the use-after-free occurs during automatic init-failure teardown or driver removal, independent of opening /dev/watchdog or other user actions.\nS:U - Impact is a kernel heap/timer use-after-free within the host kernel on an embedded AT91 SoC; it does not cross VM, container, or IOMMU security boundaries.\nC:H - The at91_ping() timer callback dereferences freed at91wdt fields (next_heartbeat, wdd, heartbeat, base) after devm release, providing sprayable arbitrary kernel memory disclosure per UAF guidance.\nI:H - Reuse of the freed at91wdt lets at91_wdt_reset() issue MMIO writes through a controlled base pointer and mod_timer() corrupt timer/heap metadata, enabling arbitrary write and control-flow hijack primitives.\nA:H - Use-after-free access from the timer softirq path to freed at91wdt memory causes kernel oops or panic even without deliberate exploitation, and can be repeated by cycling probe/removal against the still-rearming timer."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/watchdog/at91sam9_wdt.c"], "versions": [{"version": "5161b31dc39a6d6dadc95f298de48a725b73ada8", "lessThan": "29fe74c9aa69d78c1c6a3930f1d9fc5db71a6eed", "status": "affected", "versionType": "git"}, {"version": "5161b31dc39a6d6dadc95f298de48a725b73ada8", "lessThan": "b7949b0a7d998013b7ec8617a0ef5b07cca80be4", "status": "affected", "versionType": "git"}, {"version": "5161b31dc39a6d6dadc95f298de48a725b73ada8", "lessThan": "8444d66aa6b6e7fe0a26fa1a00a11cb4d0523783", "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/watchdog/at91sam9_wdt.c"], "versions": [{"version": "3.14", "status": "affected"}, {"version": "0", "lessThan": "3.14", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.9", "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": "3.14", "versionEndExcluding": "6.18.45"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14", "versionEndExcluding": "7.1.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/29fe74c9aa69d78c1c6a3930f1d9fc5db71a6eed"}, {"url": "https://git.kernel.org/stable/c/b7949b0a7d998013b7ec8617a0ef5b07cca80be4"}, {"url": "https://git.kernel.org/stable/c/8444d66aa6b6e7fe0a26fa1a00a11cb4d0523783"}], "title": "watchdog: at91sam9_wdt: prevent timer rearm during teardown", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/watchdog/at91sam9_wdt.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "29fe74c9aa69d78c1c6a3930f1d9fc5db71a6eed", "status": "affected", "version": "5161b31dc39a6d6dadc95f298de48a725b73ada8", "versionType": "git"}, {"lessThan": "b7949b0a7d998013b7ec8617a0ef5b07cca80be4", "status": "affected", "version": "5161b31dc39a6d6dadc95f298de48a725b73ada8", "versionType": "git"}, {"lessThan": "8444d66aa6b6e7fe0a26fa1a00a11cb4d0523783", "status": "affected", "version": "5161b31dc39a6d6dadc95f298de48a725b73ada8", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/watchdog/at91sam9_wdt.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "3.14"}, {"lessThan": "3.14", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.45", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwatchdog: at91sam9_wdt: prevent timer rearm during teardown\n\nat91_ping() rearms the watchdog timer from its callback. timer_delete()\nneither waits for a running callback nor prevents it from rearming the\ntimer, so probe failure or driver removal can leave the timer accessing the\ndevm-allocated at91wdt after it has been freed.\n\nUse timer_shutdown_sync() on both teardown paths. It waits for a running\ncallback and rejects any attempt by the callback to rearm the timer."}], "id": "CVE-2026-74687", "lastModified": "2026-08-25T06:18:51.470", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-22T16:16:43.080", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/29fe74c9aa69d78c1c6a3930f1d9fc5db71a6eed"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8444d66aa6b6e7fe0a26fa1a00a11cb4d0523783"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b7949b0a7d998013b7ec8617a0ef5b07cca80be4"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: watchdog: at91sam9_wdt: prevent timer rearm during teardown", "id": "2521470", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521470"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nwatchdog: at91sam9_wdt: prevent timer rearm during teardown\nat91_ping() rearms the watchdog timer from its callback. timer_delete()\nneither waits for a running callback nor prevents it from rearming the\ntimer, so probe failure or driver removal can leave the timer accessing the\ndevm-allocated at91wdt after it has been freed.\nUse timer_shutdown_sync() on both teardown paths. It waits for a running\ncallback and rejects any attempt by the callback to rearm the timer.", "A flaw was found in the Linux kernel, specifically within the `at91sam9_wdt` watchdog timer driver. During the driver's teardown process, the `at91_ping()` function could rearm the watchdog timer. However, the `timer_delete()` function does not prevent this, resulting in a use-after-free vulnerability where the timer attempts to access memory that has already been released. This flaw could be triggered by a local attacker or specific system conditions, potentially leading to system instability or a denial of service."], "name": "CVE-2026-74687", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-22T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74687\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74687\nhttps://lore.kernel.org/linux-cve-announce/2026082233-CVE-2026-74687-b615@gregkh/T"], "threat_severity": "Moderate"}