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Fencer Intel
medium 5.3

CVE-2026-17559 json

Content Protector (Passster) < 4.3.9 - Unauthenticated Protected Content Disclosure via REST Path Allowlist Bypass

published 2mo ago modified 24d ago also EUVD-2026-63911

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

The Passster WordPress plugin before 4.3.9 does not correctly match its own public endpoint paths when deciding which REST API requests may bypass global password protection, comparing them as an unanchored substring of the request URI rather than against the resolved route, allowing an unauthenticated attacker to read the content of globally password-protected posts and pages.

Patch / fix

  • Unknown Passster 4.3.9

Is CVE-2026-17559 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
partial
Assessed
2mo ago

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/28a48c1c-e162-4e8a-b450-5568fb3a3fc8/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected products

  • Unknown Passster

Classification

Weakness
Technology feeds

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.