CVE-2026-86805
- Source
- https://cve.org/CVERecord?id=CVE-2026-86805
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-86805.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2026-86805
- Downstream
- Published
- 2026-09-22T15:55:17Z
- Modified
- 2026-09-23T03:47:27Z
- Severity
-
- 6.3 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:L CVSS Calculator
- Summary
- AT_SECURE programs may load attacker-controlled code via $ORIGIN
- Details
-
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/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.
Exploitation 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.
- Database specific
{ "cna_assigner": "glibc", "cwe_ids": [ "CWE-367" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86805.json", "unresolved_ranges": [ { "extracted_events": [ { "introduced": "2.14" }, { "fixed": "2.45" } ], "source": "AFFECTED_FIELD" } ] }- References