{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-98840", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-98840", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-10-18T15:50:14.029Z", "updatedAt": "2026-10-21T12:57:25.411Z", "importedAt": "2026-10-24T01:58:41.756Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "vc_screen: reload vc pointer before if (ret) in vcs_write() to avoid UAF", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nvc_screen: reload vc pointer before if (ret) in vcs_write() to avoid UAF\n\nThe reload of 'vc' added by commit 8fb9ea65c9d1 (\"vc_screen: reload load\nof struct vc_data pointer in vcs_write() to avoid UAF\") sits after the\n'if (ret)' block, so the copy-failure break path exits the loop without\nreloading vc. If the vc was kfree()'d via vc_port_destruct during the\nunlocked copy_from_user() window, the post-loop\n'if (written && vc) vcs_scr_updated(vc)' is reached with a stale\nnon-NULL vc. The '&& vc' guard from commit a287620312dc (\"vc_screen:\nfix null-ptr-deref in vcs_notifier() during concurrent vcs_write\") only\nhandles the NULL case, not this stale-non-NULL case; vcs_notifier() then\nreads param->vc->vc_num from freed memory:\n\n BUG: KASAN: slab-use-after-free in vcs_notifier+0x7c/0xd0\n Read of size 2 at addr ffff888007149190\n Call Trace:\n vcs_notifier+0x7c/0xd0\n atomic_notifier_call_chain+0x70/0xa0\n vcs_scr_updated+0x77/0xa0\n vcs_write+0x71b/0x7e0\n Allocated by task: vc_allocate -> con_install -> tty_open\n Freed by task: kfree <- vt_ioctl (VT_DISALLOCATE -> vc_port_destruct)\n\nMove the reload to immediately after console_lock(), before 'if (ret)',\nso every break path below passes a fresh vc to the post-loop\nvcs_scr_updated().", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "8232fca738011ca2ec865b46ec721d1796dc0580", "status": "affected", "versionType": "git", "lessThan": "c073d01f6f5367c3a4f07efd507274ed0d03acd0" }, { "version": "73049768ad57145acd337102c5aa3c788e6642c8", "status": "affected", "versionType": "git", "lessThan": "1485a3dd97ab1af2605243cabe6b604546d46dd1" }, { "version": "7cc3dd79777f6ae4625ec37e84dd18a26dc88bde", "status": "affected", "versionType": "git", "lessThan": "233a2e190b12884d186027d0b86d43a48799b69c" }, { "version": "a287620312dc6dcb9a093417a0e589bf30fcf38a", "status": "affected", "versionType": "git", "lessThan": "9dfcadc5e003fb250dd471db90144bd5366140e9" }, { "version": "a287620312dc6dcb9a093417a0e589bf30fcf38a", "status": "affected", "versionType": "git", "lessThan": "226bd5603371cd9f6642cbb9e9a677f445de3530" }, { "version": "43a6281790273c1b0a9ab76609ff0245b968f1e6", "status": "affected", "versionType": "git" }, { "version": "b6bbb85cf45bf0b070e741997fe0af3a772c5ad5", "status": "affected", "versionType": "git" }, { "version": "ff4806202749a51938236214adc0281481a57366", "status": "affected", "versionType": "git" }, { "version": "74be188eb2dc1c99d63986167b9a67d415fe7326", "status": "affected", "versionType": "git" }, { "version": "09a43e81279b8da15526da09877134b8bcf618b0", "status": "affected", "versionType": "git" }, { "version": "6.6.144", "status": "affected", "versionType": "semver", "lessThan": "6.6.160" }, { "version": "6.12.95", "status": "affected", "versionType": "semver", "lessThan": "6.12.113" }, { "version": "6.18.37", "status": "affected", "versionType": "semver", "lessThan": "6.18.56" }, { "version": "5.10.260", "status": "affected", "versionType": "semver", "lessThan": "5.11" }, { "version": "5.15.211", "status": "affected", "versionType": "semver", "lessThan": "5.16" }, { "version": "6.1.177", "status": "affected", "versionType": "semver", "lessThan": "6.2" }, { "version": "7.0.14", "status": "affected", "versionType": "semver", "lessThan": "7.1" }, { "version": "7.1.2", "status": "affected", "versionType": "semver", "lessThan": "7.2" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "7.2", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "7.2" }, { "version": "6.6.160", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.113", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.56", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.2.10", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.2.*" }, { "version": "7.3", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }