CVE-2020-5390

PySAML2 before 5.0.0 does not check that the signature in a SAML document is enveloped and thus signature wrapping is effective, i.e., it is affected by XML Signature Wrapping (XSW). The signature information and the node/object that is signed can be in different places and thus the signature verification will succeed, but the wrong data will be used. This specifically affects the verification of assertion that have been signed.

Published: 2020-01-13 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-5390 is rated Moderate Risk (52.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.21%). 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-2020-5390

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 0.76% 1.21% +0.44%
2 2025-12-28 0.66% 0.76% +0.10%
3 2025-12-27 — 0.66% —

Full EPSS history (22 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-5390

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
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:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-5390

GitHub Security Advisory for CVE-2020-5390

GHSA-qf7v-8hj3-4xw7 · Severity: high · Ecosystem: pip — Improper Verification of Cryptographic Signature in PySAML2

OS Trackers for CVE-2020-5390

vendor priority summary link
debian not yet assigned CVE-2020-5390 not yet assigned priority: Debian including 1 source packages (python-pysaml2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-5390
redhat high — https://access.redhat.com/security/cve/CVE-2020-5390
suse medium CVE-2020-5390 severity moderate: SUSE including 241 source package names (ansible-2.2.3.0-12.2, ansible-2.4.6.0-3.9.1, …), 422 product×package rows across 7 product lines (HPE Helion OpenStack 8, SUSE OpenStack Cloud 7, … (7 product lines)): Fixed 422. https://www.suse.com/security/cve/CVE-2020-5390/
ubuntu medium CVE-2020-5390 medium priority: Ubuntu including 1 source packages (python-pysaml2), 6 status rows across 6 suites (bionic, disco, eoan, trusty, upstream, xenial): released 4, DNE 1, needs-triage 1. https://ubuntu.com/security/CVE-2020-5390

Affected software / configurations for CVE-2020-5390

Vendor Product Version Raw CPE
pysaml2_project pysaml2 < 5.0.0 cpe:2.3:a:pysaml2_project:pysaml2:*:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 19.04 cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:*
canonical ubuntu_linux 19.10 cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2020-5390

cvelogic Threat Intelligence