ILIAS before versions 9.22, 10.10, and 11.3 contains an unauthenticated PHP object injection vulnerability that allows unauthenticated attackers to execute arbitrary code by injecting serialized objects through the LTI authentication endpoint and triggering deserialization via the Shibboleth back-channel logout endpoint. Attackers can write arbitrary serialized objects into session storage, then exploit an available POP gadget through the logout endpoint's unrestricted deserialization to write attacker-controlled PHP content to a web-accessible path and achieve remote code execution as the web server user.
This CVE has been withdrawn by MITRE
MITRE marked CVE-2026-18745 as REJECTED on . It is no longer considered a valid vulnerability record. The original content below is preserved for historical reference only.
Reason given by MITRE
This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.
CVE-2026-18745
✕ Withdrawn — historical dataCRITICALPre-NVD 9.8
9.8CVSS
- CVSS v3
- 9.8
- EchelonGraph score
- Not yet assessedThis CVE record was withdrawn by its numbering authority, so there is no vulnerability to rate.
- EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- —Not applicable: this CVE ID was withdrawn
Published
September 4, 2026
Last Modified
September 4, 2026
References (7)
- https://docu.ilias.de/ilias.php?baseClass=ilrepositorygui&cmdNode=wy:ll:6t&cmdClass=ilBlogPostingGUI&cmd=previewFullscreen&ref_id=15821&blpg=936
- https://docu.ilias.de/ilias.php?baseClass=illmpresentationgui&obj_id=225632&ref_id=35
- https://docu.ilias.de/ilias.php?baseClass=ilrepositorygui&cmdNode=wy:ll:6t&cmdClass=ilBlogPostingGUI&cmd=previewFullscreen&ref_id=15821&blpg=935
- https://docu.ilias.de/ilias.php?baseClass=illmpresentationgui&obj_id=225631&ref_id=35
- https://docu.ilias.de/ilias.php?baseClass=ilrepositorygui&cmdNode=wy:ll:6t&cmdClass=ilBlogPostingGUI&cmd=previewFullscreen&ref_id=15821&blpg=934
- https://docu.ilias.de/ilias.php?baseClass=illmpresentationgui&obj_id=225630&ref_id=35
- https://www.vulncheck.com/advisories/ilias-php-object-injection-via-shibboleth-logout
Frequently asked(4)
What is CVE-2026-18745?
CVE-2026-18745 is a rejected CVE ID: its record was withdrawn on September 4, 2026 and no longer describes a vulnerability. Reason given: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.
When was the CVE record for CVE-2026-18745 published?
The CVE record for CVE-2026-18745 was published on September 4, 2026. EchelonGraph's copy of the record carries a last-modified date of September 4, 2026; the record at its source may have been updated since.
What is the CVSS score of CVE-2026-18745?
CVE-2026-18745 has a CVSS base score of 9.8 (the CNA's own assessment, by vulncheck; NVD's own analysis pending).
How do I remediate CVE-2026-18745?
There is nothing to remediate under CVE-2026-18745: it is a rejected (withdrawn) CVE ID and no longer describes a vulnerability.