{"id":"CVE-2026-80663","state":"PUBLISHED","title":"tools/power/x86/intel-speed-select: Harden daemon pidfile open","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntools/power/x86/intel-speed-select: Harden daemon pidfile open\n\nAvoid symlink-based pidfile clobbering by opening the pidfile with\nO_NOFOLLOW and validating it with fstat() before locking/writing.\n\nThe daemon currently uses a fixed pidfile path under /tmp. A local\nunprivileged user can pre-create a symlink at that path and cause a\nroot-run daemon instance to write into an attacker-chosen file.","publishedAt":"2026-08-28T06:49:06.882Z","updatedAt":"2026-10-16T19:26:32.045Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"905493a6338c82a70da16f86e0a6215db5a3d73d","versionType":"git"},{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"db938eb9a3c1317596c28e94413b33426508d51b","versionType":"git"},{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"72a07abc6b9046f07a08bba353cad7667bcc9dce","versionType":"git"},{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"19ffeb30fdfce63f8d6aca71bcdddb3f69d46278","versionType":"git"},{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"e8adac69d1bdf035ef97cc914e845acd4ef08e28","versionType":"git"},{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"607af438e6430893a822964c841a1994b33acccc","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["tools/power/x86/intel-speed-select/isst-daemon.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.18","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["tools/power/x86/intel-speed-select/isst-daemon.c"]}],"references":["https://git.kernel.org/stable/c/905493a6338c82a70da16f86e0a6215db5a3d73d","https://git.kernel.org/stable/c/db938eb9a3c1317596c28e94413b33426508d51b","https://git.kernel.org/stable/c/72a07abc6b9046f07a08bba353cad7667bcc9dce","https://git.kernel.org/stable/c/19ffeb30fdfce63f8d6aca71bcdddb3f69d46278","https://git.kernel.org/stable/c/e8adac69d1bdf035ef97cc914e845acd4ef08e28","https://git.kernel.org/stable/c/607af438e6430893a822964c841a1994b33acccc"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80663.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80663","state":"PUBLISHED","datePublished":"2026-08-28T06:49:06.882Z","dateUpdated":"2026-10-16T19:26:32.045Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.781Z"},"containers":{"cna":{"title":"tools/power/x86/intel-speed-select: Harden daemon pidfile open","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntools/power/x86/intel-speed-select: Harden daemon pidfile open\n\nAvoid symlink-based pidfile clobbering by opening the pidfile with\nO_NOFOLLOW and validating it with fstat() before locking/writing.\n\nThe daemon currently uses a fixed pidfile path under /tmp. A local\nunprivileged user can pre-create a symlink at that path and cause a\nroot-run daemon instance to write into an attacker-chosen file."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"905493a6338c82a70da16f86e0a6215db5a3d73d","versionType":"git"},{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"db938eb9a3c1317596c28e94413b33426508d51b","versionType":"git"},{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"72a07abc6b9046f07a08bba353cad7667bcc9dce","versionType":"git"},{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"19ffeb30fdfce63f8d6aca71bcdddb3f69d46278","versionType":"git"},{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"e8adac69d1bdf035ef97cc914e845acd4ef08e28","versionType":"git"},{"version":"7fd786dfbd2c55ddee3b87f33c82f1c58bdb1dd6","status":"affected","lessThan":"607af438e6430893a822964c841a1994b33acccc","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["tools/power/x86/intel-speed-select/isst-daemon.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.18","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["tools/power/x86/intel-speed-select/isst-daemon.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/905493a6338c82a70da16f86e0a6215db5a3d73d"},{"url":"https://git.kernel.org/stable/c/db938eb9a3c1317596c28e94413b33426508d51b"},{"url":"https://git.kernel.org/stable/c/72a07abc6b9046f07a08bba353cad7667bcc9dce"},{"url":"https://git.kernel.org/stable/c/19ffeb30fdfce63f8d6aca71bcdddb3f69d46278"},{"url":"https://git.kernel.org/stable/c/e8adac69d1bdf035ef97cc914e845acd4ef08e28"},{"url":"https://git.kernel.org/stable/c/607af438e6430893a822964c841a1994b33acccc"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Exploitation requires local filesystem access to plant a symlink at the fixed /tmp/hfi-events.pid path before the root-run intel-speed-select --oob daemon calls open(); there is no network, adjacent, or physical-device code path to daemonize().\nAC:L - The attacker fully controls symlink creation in world-writable /tmp and can leave it in place until the root daemon starts or restarts (e.g., via systemd on Sapphire Rapids datacenter hosts); no uncontrollable timing or memory-layout conditions are required.\nPR:L - Only an unprivileged local account is needed to create the /tmp/hfi-events.pid symlink; the attacker does not need init-namespace root, CAP_SYS_ADMIN, or any capability beyond ordinary local shell access.\nUI:N - Per CVSS 3.1, administrator installation or routine execution of the vulnerable daemon is not counted as user interaction; once the root OOB service is running, the attacker needs only the pre-planted symlink with no further victim action.\nS:U - The root daemon's misdirected open/write affects host filesystem objects within the same OS security authority; this is a local root-assisted file clobber, not a VM escape, container breakout, or IOMMU boundary bypass.\nC:N - The daemon only writes a short numeric PID string via write() and never reads from the opened descriptor; there is no memory corruption, out-of-bounds read, or other information-disclosure primitive.\nI:H - A symlink causes the root daemon's open(O_RDWR|O_CREAT) to follow into an attacker-chosen path, letting root truncate/overwrite the start of protected files (e.g., /etc/passwd, sudoers, unit files) or create new root-owned files in restricted directories.\nA:H - Overwriting the beginning of critical configuration or authentication files with root privileges can break login, service startup, or ISST OOB management, producing system-wide denial of service beyond a single daemon crash."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-29T06:21:48.835Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-80663","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T19:19:25.728205Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:26:32.045Z"}}]}}}