CVE-2026-86805 Affecting glibc package, versions <2.41-12+deb13u4+e3


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.12% (3rd percentile)

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  • Snyk IDSNYK-ECHOLATEST-GLIBC-20059423
  • published23 Sept 2026
  • disclosed22 Sept 2026

Introduced: 22 Sep 2026

NewCVE-2026-86805  (opens in a new tab)

How to fix?

Upgrade Echo:latest glibc to version 2.41-12+deb13u4+e3 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream glibc package and not the glibc package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1