Apereo CAS ResponseEntity redos

published 2025-04-27 18 mo ago modified 2026-06-17 4 mo ago also GHSA-8rx4-fxq5-vj4v , EUVD-2025-12427

cvss: 2.7; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits: 0; none known

A vulnerability was found in Apereo CAS 5.2.6. It has been classified as problematic. This affects the function ResponseEntity of the file cas-5.2.6\webapp-mgmt\cas-management-webapp-support\src\main\java\org\apereo\cas\mgmt\services\web\ManageRegisteredServicesMultiActionController.java. The manipulation of the argument Query leads to inefficient regular expression complexity. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 18 mo ago (2025-04-28)

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

wx.mail.qq.com https://wx.mail.qq.com/s?k=lzDuxVkSRXUZ0bwZEG referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CNA	3.1	2.7	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L
CNA	3.0	2.7	CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L
CNA	2.0	3.3	AV:N/AC:L/Au:M/C:N/I:N/A:P
CNA	4.0	5.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/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
NVD	3.1	4.9	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
GitHub	3.1	2.7	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem	package	affected	fixed in
maven	org.apereo.cas:cas-management-webapp-support	<=5.2.6	no fix listed

Affected products

Apereo CAS

Classification

Weakness

CWE-1333 Inefficient Regular Expression Complexity
CWE-400 Uncontrolled Resource Consumption

References

wx.mail.qq.com /s?k=lzDuxVkSRXUZ0bwZEG
exploit, web, not-applicable
vuldb.com /?id.306321
vdb-entry, technical-description, web, third-party-advisory
vuldb.com /?ctiid.306321
signature, permissions-required, web, vdb-entry
vuldb.com /?submit.557110
third-party-advisory, web, vdb-entry
nvd.nist.gov /vuln/detail/CVE-2025-3985
advisory
github.com /apereo/cas
package

Sources

CVE List CVE-2025-3985
GitHub Advisory GHSA-8rx4-fxq5-vj4v
NVD CVE-2025-3985

Fencer Vulns 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.

Summary