CVE-2026-89585

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89585", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.729Z", "datePublished": "2026-09-11T19:44:50.592Z", "dateUpdated": "2026-10-19T08:49:17.989Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:49:17.989Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nauxdisplay: charlcd: cancel backlight work on registration failure\n\nWith CONFIG_CHARLCD_BL_FLASH, charlcd_init() schedules bl_work before\ncharlcd_register() calls misc_register(). If registration fails, the\ncaller frees the charlcd object while delayed work still contains its\naddress.\n\nAdd charlcd_deinit() to cancel the delayed work and turn the backlight\noff. Use it for both registration rollback and normal unregistration."}], "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 - charlcd_register() is reached only from local auxdisplay probe (hd44780 platform, lcd2s I2C, panel parport) on character LCDs in embedded, industrial, and appliance systems; there is no network or USB-host packet path into this misc-registration error path.\nAC:L - CONFIG_CHARLCD_BL_FLASH is the default, so charlcd_init() always queues bl_work (L* poke, 4s) before misc_register(); a second charlcd consumer or LCD_MINOR 156 collision makes registration fail deterministically, then the work runs on the freed object with no attacker-uncontrollable race.\nPR:L - On multi-display or mixed hd44780/lcd2s/panel systems the second probe runs automatically at boot without init-namespace root, and an unprivileged local user can spray the heap in the 4s window; embedded/kiosk sysfs bind is also not strictly root-only. Uncertain vs High, so Low.\nUI:N - The UAF is armed during driver probe and consumed by the kernel workqueue; no victim needs to open /dev/lcd, mount a filesystem, or take any other interactive action.\nS:U - The delayed-work UAF corrupts in-kernel charlcd_priv/work_struct heap state and can escalate only within the host kernel; it does not cross a VM, IOMMU, or sandbox boundary.\nC:H - charlcd_bl_off() does container_of() on the freed delayed_work and reads priv fields, including lcd.ops, from reclaimable slab, giving a use-after-free kernel read primitive.\nI:H - The same callback invokes priv->lcd.ops->backlight on the freed object, so reclaiming the slab with a forged ops table yields a kernel function-pointer call, arbitrary write, and control-flow hijack.\nA:H - Running delayed work after charlcd_free() oopses or panics via mutex_lock on freed bl_tempo_lock or a wild ops pointer, even when the UAF is not fully exploited."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/auxdisplay/charlcd.c"], "versions": [{"version": "39f8ea46724efbed3ca021863a22337c31be264c", "lessThan": "cd97b3c68fe3c06c8067cc59d7dff976c5b7ea04", "status": "affected", "versionType": "git"}, {"version": "39f8ea46724efbed3ca021863a22337c31be264c", "lessThan": "22586432c1aba89d9bd33f3173408dac830f220b", "status": "affected", "versionType": "git"}, {"version": "39f8ea46724efbed3ca021863a22337c31be264c", "lessThan": "6eaed64a32e550daf0dc9549742b3ab9e41d984f", "status": "affected", "versionType": "git"}, {"version": "39f8ea46724efbed3ca021863a22337c31be264c", "lessThan": "fe7ba73dde94c5f413b1588cd444b49105015dda", "status": "affected", "versionType": "git"}, {"version": "39f8ea46724efbed3ca021863a22337c31be264c", "lessThan": "84858671842ae5857b9ed1202b62f9045373dcd1", "status": "affected", "versionType": "git"}, {"version": "39f8ea46724efbed3ca021863a22337c31be264c", "lessThan": "ff2fb3c1e60cb247ea3e28c0ea0bea81c18f7755", "status": "affected", "versionType": "git"}, {"version": "39f8ea46724efbed3ca021863a22337c31be264c", "lessThan": "e3e3bf40916c1e810df03958cfa7ba6883cdce79", "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/auxdisplay/charlcd.c"], "versions": [{"version": "4.12", "status": "affected"}, {"version": "0", "lessThan": "4.12", "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", "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": "4.12", "versionEndExcluding": "5.15.221"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.1.188"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.6.157"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.12.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/cd97b3c68fe3c06c8067cc59d7dff976c5b7ea04"}, {"url": "https://git.kernel.org/stable/c/22586432c1aba89d9bd33f3173408dac830f220b"}, {"url": "https://git.kernel.org/stable/c/6eaed64a32e550daf0dc9549742b3ab9e41d984f"}, {"url": "https://git.kernel.org/stable/c/fe7ba73dde94c5f413b1588cd444b49105015dda"}, {"url": "https://git.kernel.org/stable/c/84858671842ae5857b9ed1202b62f9045373dcd1"}, {"url": "https://git.kernel.org/stable/c/ff2fb3c1e60cb247ea3e28c0ea0bea81c18f7755"}, {"url": "https://git.kernel.org/stable/c/e3e3bf40916c1e810df03958cfa7ba6883cdce79"}], "title": "auxdisplay: charlcd: cancel backlight work on registration failure", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/auxdisplay/charlcd.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "cd97b3c68fe3c06c8067cc59d7dff976c5b7ea04", "status": "affected", "version": "39f8ea46724efbed3ca021863a22337c31be264c", "versionType": "git"}, {"lessThan": "22586432c1aba89d9bd33f3173408dac830f220b", "status": "affected", "version": "39f8ea46724efbed3ca021863a22337c31be264c", "versionType": "git"}, {"lessThan": "6eaed64a32e550daf0dc9549742b3ab9e41d984f", "status": "affected", "version": "39f8ea46724efbed3ca021863a22337c31be264c", "versionType": "git"}, {"lessThan": "fe7ba73dde94c5f413b1588cd444b49105015dda", "status": "affected", "version": "39f8ea46724efbed3ca021863a22337c31be264c", "versionType": "git"}, {"lessThan": "84858671842ae5857b9ed1202b62f9045373dcd1", "status": "affected", "version": "39f8ea46724efbed3ca021863a22337c31be264c", "versionType": "git"}, {"lessThan": "ff2fb3c1e60cb247ea3e28c0ea0bea81c18f7755", "status": "affected", "version": "39f8ea46724efbed3ca021863a22337c31be264c", "versionType": "git"}, {"lessThan": "e3e3bf40916c1e810df03958cfa7ba6883cdce79", "status": "affected", "version": "39f8ea46724efbed3ca021863a22337c31be264c", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/auxdisplay/charlcd.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.12"}, {"lessThan": "4.12", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.221", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.188", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.157", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "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\nauxdisplay: charlcd: cancel backlight work on registration failure\n\nWith CONFIG_CHARLCD_BL_FLASH, charlcd_init() schedules bl_work before\ncharlcd_register() calls misc_register(). If registration fails, the\ncaller frees the charlcd object while delayed work still contains its\naddress.\n\nAdd charlcd_deinit() to cancel the delayed work and turn the backlight\noff. Use it for both registration rollback and normal unregistration."}], "id": "CVE-2026-89585", "lastModified": "2026-10-19T09:17:54.653", "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": "2026-09-11T20:19:42.910", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/22586432c1aba89d9bd33f3173408dac830f220b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6eaed64a32e550daf0dc9549742b3ab9e41d984f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/84858671842ae5857b9ed1202b62f9045373dcd1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cd97b3c68fe3c06c8067cc59d7dff976c5b7ea04"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e3e3bf40916c1e810df03958cfa7ba6883cdce79"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fe7ba73dde94c5f413b1588cd444b49105015dda"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ff2fb3c1e60cb247ea3e28c0ea0bea81c18f7755"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel: Use-after-free in auxdisplay charlcd component", "id": "2532284", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532284"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.4", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["A flaw was found in the `auxdisplay: charlcd` component of the Linux kernel. This use-after-free vulnerability occurs when the `charlcd_register()` function fails, leading to the `charlcd` object being freed while a delayed work item still retains its address. A local attacker could potentially exploit this to cause a system crash or other undefined behavior."], "name": "CVE-2026-89585", "public_date": "2026-09-11T19:44:50Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89585\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89585\nhttps://git.kernel.org/stable/c/84858671842ae5857b9ed1202b62f9045373dcd1\nhttps://git.kernel.org/stable/c/e3e3bf40916c1e810df03958cfa7ba6883cdce79\nhttps://git.kernel.org/stable/c/fe7ba73dde94c5f413b1588cd444b49105015dda\nhttps://git.kernel.org/stable/c/ff2fb3c1e60cb247ea3e28c0ea0bea81c18f7755"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[39f8ea46724efbed3ca021863a22337c31be264c,fe7ba73dde94c5f413b1588cd444b49105015dda)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[39f8ea46724efbed3ca021863a22337c31be264c,84858671842ae5857b9ed1202b62f9045373dcd1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[39f8ea46724efbed3ca021863a22337c31be264c,ff2fb3c1e60cb247ea3e28c0ea0bea81c18f7755)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[39f8ea46724efbed3ca021863a22337c31be264c,e3e3bf40916c1e810df03958cfa7ba6883cdce79)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "4.12"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,4.12)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.109,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.50,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.4,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-12T04:15:05.729010+00:00", "updated": "2026-09-15T21:45:17.658837+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}