How severe is CVE-2020-5390?

CVE-2020-5390 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2020-5390 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-5390?

CVE-2020-5390 primarily affects Pysaml2 Project Pysaml2. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-5390?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-5390 published?

CVE-2020-5390 was published on 2020-01-13 and last updated on 2026-06-17.

CVE-2020-5390

CVE-2020-5390 is a high-severity vulnerability in Pysaml2 Project Pysaml2 with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-347.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-347
Affected product: Pysaml2 Project Pysaml2
Published: 2020-01-13
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2020-5390?: CVE-2020-5390 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2020-5390 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5390?: CVE-2020-5390 primarily affects Pysaml2 Project Pysaml2. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-5390?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-5390 published?: CVE-2020-5390 was published on 2020-01-13 and last updated on 2026-06-17.

References

Affected products (8)

cpe:2.3:a:pysaml2_project:pysaml2:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

More vulnerabilities in Pysaml2 Project Pysaml2

CVE-2016-10127 — Critical (CVSS 9.0): PySAML2 allows remote attackers to conduct XML external entity (XXE) attacks via a crafted SAML XML request or response.
CVE-2017-1000433 — High (CVSS 8.1): pysaml2 version 4.4.0 and older accept any password when run with python optimizations enabled. This allows attackers…
CVE-2016-10149 — High (CVSS 7.5): XML External Entity (XXE) vulnerability in PySAML2 4.4.0 and earlier allows remote attackers to read arbitrary files…
CVE-2021-21239 — Medium (CVSS 6.5): PySAML2 is a pure python implementation of SAML Version 2 Standard. PySAML2 before 6.5.0 has an improper verification…
CVE-2021-21238 — Medium (CVSS 6.5): PySAML2 is a pure python implementation of SAML Version 2 Standard. PySAML2 before 6.5.0 has an improper verification…
CVE-2017-1000246 — Medium (CVSS 5.3): Python package pysaml2 version 4.4.0 and earlier reuses the initialization vector across encryptions in the IDP server,…

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