How severe is CVE-2020-36255?

CVE-2020-36255 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-2020-36255 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-36255?

CVE-2020-36255 affects Identitymodel Project Identitymodel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-36255?

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-2020-36255 published?

CVE-2020-36255 was published on 2021-03-05 and last updated on 2026-06-17.

CVE-2020-36255

CVE-2020-36255 is a high-severity vulnerability in Identitymodel Project Identitymodel 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.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Identitymodel Project Identitymodel
Published: 2021-03-05
Last modified: 2026-06-17

Description

An issue was discovered in IdentityModel (aka ScottBrady.IdentityModel) before 1.3.0. The Branca implementation allows an attacker to modify and forge authentication tokens.

Frequently asked questions

What is CVE-2020-36255?: An issue was discovered in IdentityModel (aka ScottBrady.IdentityModel) before 1.3.0. The Branca implementation allows an attacker to modify and forge authentication tokens.
How severe is CVE-2020-36255?: CVE-2020-36255 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-2020-36255 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-36255?: CVE-2020-36255 affects Identitymodel Project Identitymodel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-36255?: 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-2020-36255 published?: CVE-2020-36255 was published on 2021-03-05 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:identitymodel_project:identitymodel:*:*:*:*:*:*:*:*