CVE-2026-49284 json
SimpleSAMLphp SP accepts a response from an unexpected IdP when unsigned `Response/InResponseTo` is combined with a signed assertion lacking `SubjectConfirmationData/InResponseTo`
published 2026-07-02 4 mo ago modified 2026-09-10 1 mo ago also EUVD-2026-45284 , GHSA-q8r6-xj3f-wrrm
- cvss
- 7.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 12%
- public exploits
- 0
- none known
Summary
SimpleSAMLphp versions before 1.18.6 contain an information disclosure vulnerability. Prior to 2.4.7 and 2.5.2, SimpleSAMLphp's SAML SP ACS path does not enforce the IdP selected for an SP-initiated login when unsigned Response/InResponseTo is combined with a signed assertion lacking SubjectConfirmationData/InResponseTo, allowing a response issued by one trusted IdP to be bound to SP state created for another IdP and bypass flows that route users to a specific IdP, including deployments that set enable_unsolicited to false. This issue is fixed in versions 2.4.7 and 2.5.2.
Patch / fix
- packagist simplesamlphp/simplesamlphp 2.4.7, 2.5.2
- simplesamlphp simplesamlphp 2.4.7, 2.5.2
- simplesamlphp Debian 14 2.4.8-1
debian advisories DEBIAN-CVE-2026-49284
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N |
| GitHub | 3.1 | 7.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | simplesamlphp/simplesamlphp | >=2.5.0, <2.5.2 <2.4.7 |
2.5.2 2.4.7 |
Affected products
- simplesamlphp simplesamlphp
Classification
- Weakness
-
- CWE-345 Insufficient Verification of Data Authenticity
References
-
github.com
/simplesamlphp/simplesamlphp/security/advisories/GHSA-q8r6-xj3f-wrrm
web, vendor-advisory
-
github.com
/simplesamlphp/simplesamlphp/releases/tag/v2.4.7
product, release-notes
-
github.com
/simplesamlphp/simplesamlphp/releases/tag/v2.5.2
product, release-notes
-
github.com
/simplesamlphp/simplesamlphp
package
Sources
- CVE List CVE-2026-49284
- GitHub Advisory GHSA-q8r6-xj3f-wrrm
- NVD CVE-2026-49284
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.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.