What is CVE-2018-7711?

CVE-2018-7711 is a high-severity vulnerability in Simplesamlphp Saml2, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.1/10. Published 2018-03-05.

How severe is CVE-2018-7711?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Simplesamlphp Saml2

CVE-2018-7711

HTTPRedirect.php in the saml2 library in SimpleSAMLphp before 1.15.4 has an incorrect check of return values in the signature validation utilities, allowing an attacker to get invalid signatures accepted as valid by forcing an error during validation. This occurs because of a dependency on PHP functionality that interprets a -1 error code as a true boolean value.

Published 2018-03-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.012 (66.7th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 66.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: +0.000

Affected products

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

github.com/simplesamlphp/saml2/commit/4f6af7f69f29df8555a18b9bb7b646906b45924d (Patch)
lists.debian.org/debian-lts-announce/2018/03/msg00017.html (mailing-list, Third Party Advisory)
simplesamlphp.org/security/201803-01 (Vendor Advisory)

Frequently asked questions

What is CVE-2018-7711?: CVE-2018-7711 is a high-severity vulnerability in Simplesamlphp Saml2, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.1/10. Published 2018-03-05.
How severe is CVE-2018-7711?: High severity. CVSS v3 base score is 8.1 out of 10.