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Fencer Vulns
medium 5.8

CVE-2026-76925 json

Flatpak: flatpak: toctou race condition allows symlink redirection

published 2026-09-04 2 mo ago modified 2026-11-06 3 d ago also EUVD-2026-71774

cvss
5.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 0%
public exploits
0
none known

Summary

A flaw was found in Flatpak. A Time-of-check to time-of-use (TOCTOU) race condition exists in the `org.freedesktop.Flatpak.SystemHelper` component. This vulnerability occurs because a privileged `chmod` operation executes before the OSTree repository validation within the `Deploy()` function. An attacker can exploit this timing window to redirect symlinks to arbitrary files, potentially leading to unauthorized file manipulation or information disclosure.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-76925 updated cvss 5.8

flatpak: Flatpak: TOCTOU race condition allows symlink redirection

  • Red Hat Enterprise Linux 7 flatpak, flatpak-libs, flatpak-builder Red Hat Enterprise Linux 8 flatpak, flatpak-libs, flatpak-selinux, flatpak-session-helper Red Hat Enterprise Linux 9 flatpak, flatpak-libs, flatpak-selinux, flatpak-session-helper Red Hat Enterprise Linux 10 flatpak
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.10% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.8 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9

Classification

Weakness
  • CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.