CVE-2021-31826

Name: CVE-2021-31826
Creator: NVD / NIST
Published: 2021-04-27T04:15:08.55+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 2.00%

Last modified Jun 17, 2026

CVE-2021-31826 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Shibboleth Service Provider 3.x before 3.2.2 is prone to a NULL pointer dereference flaw involving the session recovery feature. The flaw is exploitable (for a daemon crash) on systems not using this feature if a crafted cookie is supplied.. EPSS estimates a 2.00% chance of exploitation in the next 30 days.

Description

Shibboleth Service Provider 3.x before 3.2.2 is prone to a NULL pointer dereference flaw involving the session recovery feature. The flaw is exploitable (for a daemon crash) on systems not using this feature if a crafted cookie is supplied.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

2.00%

78.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-476

Affected Software

Vendor	Product	Versions
Shibboleth	Service Provider	>= 3.0.0, < 3.2.2

References

https://bugs.debian.org/987608Mailing List, Third Party Advisory
https://git.shibboleth.net/view/?p=cpp-sp.git%3Ba=commit%3Bh=5a47c3b9378f4c49392dd4d15189b70956f9f2ec
https://issues.shibboleth.net/jira/browse/SSPCPP-927Exploit, Patch, Vendor Advisory
https://shibboleth.net/community/advisories/secadv_20210426.txtVendor Advisory
https://www.debian.org/security/2021/dsa-4905Third Party Advisory
https://bugs.debian.org/987608Mailing List, Third Party Advisory
https://git.shibboleth.net/view/?p=cpp-sp.git%3Ba=commit%3Bh=5a47c3b9378f4c49392dd4d15189b70956f9f2ec
https://issues.shibboleth.net/jira/browse/SSPCPP-927Exploit, Patch, Vendor Advisory
https://shibboleth.net/community/advisories/secadv_20210426.txtVendor Advisory
https://www.debian.org/security/2021/dsa-4905Third Party Advisory

Timeline

Published: Apr 27, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31826?

How severe is CVE-2021-31826?

CVE-2021-31826 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 2.00% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31826?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-31826?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST