YesWiki Vulnerable to Authenticated PHP Object Injection in BazarImportAction via unserialize

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

9.4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H · score source

EPSS

• CVE-2026-52777: 0.28% estimated exploitation activity in the next 30 days; percentile 20.14 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Details Sink tools/bazar/services/CSVManager.php line 372-399: There is no ['allowedclasses' = false] argument; arbitrary classes are instantiated. The subsequent arraymap('strval', $entry) additionally exercises toString on each top-level array element, doubling the magic-method surface available to a gadget chain. Source tools/bazar/actions/BazarImportAction.php: $POST['importfiche'] flows directly to the sink. The mode switches to 'importentries' whenever the request body contains the key, so an attacker need only POST importfiche[0]=<payload. Reachability 1. The action is registered as bazarimport. The default BazaR page (setup/sql/default-content.sql - BazaR page entry, ships with {{bazar showexportbuttons="1"}}) routes ?BazaR&vue=importer&idtypeannonce=<N to BazarAction::run() - case VOIRIMPORTER - callAction('bazarimport', ...) (tools/bazar/actions/BazarAction.php:257-258). So the sink is reachable on a default install with no extra page authoring. 2. BazarImportAction::run()…

Published by the source

9 Jul 2026, 21:02 UTC

Last modified by the source

9 Jul 2026, 21:02 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-9369-69wj-7m2f

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-52777

Advisory: YesWiki Vulnerable to Authenticated PHP Object Injection in BazarImportAction via unserialize
IDs: CVE-2026-52777, GHSA-9369-69wj-7m2f
Record: https://patchnext.com/advisories/cve-2026-52777 (revision 1, source checked 26 Oct 2026, 14:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: yeswiki/yeswiki 4.6.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist yeswiki/yeswiki: affected < 4.6.6; fixed in 4.6.6

## Suggested inspection (read-only)
- Packagist yeswiki/yeswiki: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on yeswiki/yeswiki.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-9369-69wj-7m2f (GitHub-reviewed advisory GHSA-9369-69wj-7m2f lists affected ranges: Packagist yeswiki/yeswiki >=0 <4.6.6)

Commands are suggestions: review each one before running it.