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Fencer Intel
critical 9.8

CVE-2026-48611 json

Improper authentication checks in the OAuth implementation allow account hijacking even when OAuth is not configured or enabled leading to…

published 5mo ago modified 4mo ago also EUVD-2026-36375

cvss
9.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
3.9%
EPSS 3.9% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

Improper authentication checks in the OAuth implementation allow account hijacking even when OAuth is not configured or enabled leading to unauthorized access in default installations.

Patch / fix

  • phpbb phpbb 3.3.17

Is CVE-2026-48611 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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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
4mo ago

Exploit prediction

3.86% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • phpBB phpBB

Classification

Weakness

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.