{"id":"CVE-2026-86805","title":"A time-of-check to time-of-use (TOCTOU) race condition in the dynamic loader (ld.so) of the GNU C Library (glibc) versions 2.14 through 2.44 allows a local attacker to escalate privileges","summary":"A time-of-check to time-of-use (TOCTOU) race condition in the dynamic loader (ld.so) of the GNU C Library (glibc) versions 2.14 through 2.44 allows a local attacker to escalate privileges. When expanding $ORIGIN in DT_RPATH for setuid/se…","severity":"medium","cvss":6.3,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:L","cwe":["CWE-367"],"vendor":"The GNU C Library","product":"glibc","affected":["glibc >= 2.14 < 2.45"],"published":"2026-09-22","updated":"2026-09-23","sourceUpdated":"2026-09-23T04:17:57.137","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-86805","references":[{"url":"https://sourceware.org/bugzilla/show_bug.cgi?id=34360","label":"3ff69d7a-14f2-4f67-a097-88dee7810d18"},{"url":"https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0022","label":"3ff69d7a-14f2-4f67-a097-88dee7810d18"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-86805.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-86805"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2538209"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-86805"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86805"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-09-22T16:41:27.955407Z"},"ingestedAt":"2026-09-22T16:06:00.471Z","scores":{"nvd":6.3,"vendor":7},"slug":"CVE-2026-86805","body":"## Overview\n\nA time-of-check to time-of-use (TOCTOU) race condition in the dynamic loader (ld.so) of the GNU C Library (glibc) versions 2.14 through 2.44 allows a local attacker to escalate privileges. When expanding $ORIGIN in DT_RPATH for setuid/setgid (AT_SECURE) programs, glibc validates the lexically normalized search path against the trusted directories but then opens the raw, un-normalized path. On systems where the Linux fs.protected_hardlinks sysctl is disabled, a local attacker who hard-links such a program into an attacker-controlled directory and wins a race to replace an intermediate path component with a symbolic link can direct the loader outside the trusted directory, causing it to load an attacker-controlled shared object and execute arbitrary code with the elevated privileges of the program.\n\nExploitation requires an installed setuid or setgid binary whose DT_RPATH uses $ORIGIN followed by \"..\" traversal that normalizes into a trusted directory, and the ability to hard-link that binary and win the race by swapping a path component for a symbolic link. Major Linux-based OS distributions ship with fs.protected_hardlinks enabled by default and mitigate the vulnerability.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat OpenShift Container Platform 4 · updated 2026-09-22 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-86805.json)","depth":"sunlit","depthScore":35,"depthScoreParts":{"impact":34.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":209256,"id":"CVE-2026-86805","ts":1790100532077,"field":"cvss","old":"7","new":"6.3"},{"seq":209255,"id":"CVE-2026-86805","ts":1790100532077,"field":"severity","old":"high","new":"medium"}]}