CVE-2026-86805 AT_SECURE programs may load attacker-controlled code via $ORIGIN
Local attackers can escalate privileges by exploiting a race condition in glibc's dynamic loader to execute arbitrary code via attacker-controlled shared objects.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-86805?
CVE-2026-86805 is a medium-severity vulnerability in The GNU C Library glibc, published on 22 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-367
Which versions are affected by CVE-2026-86805?
Linux distribution packages (1)
glibc SUSE:Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | All versions | 2.11.3-17.110.58.1 |
How do I fix CVE-2026-86805?
Apply the vendor's patch.
Is CVE-2026-86805 being exploited?
There is no known exploitation of CVE-2026-86805 in the wild and no public exploit code.
Sources
Also known as AZL-103413, DEBIAN-CVE-2026-86805, ECHO-3f84-a5f3-00c4, GHSA-fmf4-pr35-46c2, SUSE-SU-2026:4669-1, UBUNTU-CVE-2026-86805.