CVE-2016-9955

The SimpleSAML_XML_Validator class constructor in SimpleSAMLphp before 1.14.11 might allow remote attackers to spoof signatures on SAML 1 responses or possibly cause a denial of service (memory consumption) by leveraging improper conversion of return values to boolean.

Published: 2017-02-16 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-9955 is rated Moderate Risk (48.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.19%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-9955

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.41% 1.19% +0.78%
2 2025-03-30 0.57% 0.41% -0.16%
3 2025-03-29 — 0.57% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-9955

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.3 3.0 MEDIUM
CVSS:3.0/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.0 5.2 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:H/Au:N/C:N/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:H)
Exploitation requires uncommon or highly specific conditions.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 4.9 4.9 [email protected]

Weakness enumeration for CVE-2016-9955

GitHub Security Advisory for CVE-2016-9955

GHSA-p9cm-r7jg-8q3g · Severity: medium · Ecosystem: composer — Incorrect signature verification in SimpleSAMLphp

OS Trackers for CVE-2016-9955

vendor priority summary link
debian low CVE-2016-9955 low priority: Debian including 1 source packages (simplesamlphp), 4 status rows across 4 suites (bookworm, bullseye, forky, sid): resolved 4. https://security-tracker.debian.org/tracker/CVE-2016-9955
ubuntu medium CVE-2016-9955 medium priority: Ubuntu including 1 source packages (simplesamlphp), 23 status rows across 23 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, precise, questing, trusty, upstream, xenial, yakkety, zesty): not-affected 18, ignored 2, DNE 1, needed 1, released 1. https://ubuntu.com/security/CVE-2016-9955

Affected software / configurations for CVE-2016-9955

Vendor Product Version Raw CPE
simplesamlphp simplesamlphp < 1.14.11 cpe:2.3:a:simplesamlphp:simplesamlphp:*:*:*:*:*:*:*:*
debian debian_linux 7.0 cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*

References for CVE-2016-9955

cvelogic Threat Intelligence