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Fencer Intel
medium 5.8

CVE-2026-25704 json

Incomplete privilege drop for com.system76.CosmicGreeter.GetUserData

published 7mo ago modified 4mo ago also EUVD-2026-17067

cvss
5.8
version 4.0, 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 Privilege Dropping / Lowering Errors/Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in  cosmic-greeter can allow an attacker to regain privileges that should have been dropped and abuse them in the racy checking logic.

This issue affects cosmic-greeter before https://github.Com/pop-os/cosmic-greeter/pull/426.

Is CVE-2026-25704 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2026-25704 updated cvss 7.0

cosmic-greeter: cosmic-greeter: Privilege escalation via TOCTOU race condition

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

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
7mo ago

Exploit prediction

0.08% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 4.0 5.8 CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
CNA 4.0 5.8 CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • pop-os cosmic-greeter

Classification

Weakness
  • CWE-271 Privilege Dropping / Lowering Errors
  • CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition

References

Sources

Fencer Intel 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.