How severe is CVE-2021-35473?

CVE-2021-35473 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-35473 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-35473?

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

Does CVE-2021-35473 have an EU (EUVD) identifier?

Yes. CVE-2021-35473 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-22115.

When was CVE-2021-35473 published?

CVE-2021-35473 was published on 2024-11-10 and last updated on 2026-06-17.

CVE-2021-35473

CVE-2021-35473 is a critical-severity vulnerability with a CVSS 3.x base score of 9.1. 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-613.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-22115
Weakness: CWE-613
Published: 2024-11-10
Last modified: 2026-06-17

Description

An issue was discovered in LemonLDAP::NG before 2.0.12. There is a missing expiration check in the OAuth2.0 handler, i.e., it does not verify access token validity. An attacker can use a expired access token from an OIDC client to access the OAuth2 handler The earliest affected version is 2.0.4.

Frequently asked questions

What is CVE-2021-35473?: An issue was discovered in LemonLDAP::NG before 2.0.12. There is a missing expiration check in the OAuth2.0 handler, i.e., it does not verify access token validity. An attacker can use a expired access token from an OIDC client to access the OAuth2 handler The earliest affected version is 2.0.4.
How severe is CVE-2021-35473?: CVE-2021-35473 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-35473 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-35473?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2021-35473 have an EU (EUVD) identifier?: Yes. CVE-2021-35473 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-22115.
When was CVE-2021-35473 published?: CVE-2021-35473 was published on 2024-11-10 and last updated on 2026-06-17.

References

Other CWE-613 (Insufficient Session Expiration) vulnerabilities

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CVE-2026-46455 — Critical (CVSS 9.8): Insufficient Session Expiration vulnerability in Apache Camel Keycloak Component. The camel-keycloak security helper…
CVE-2026-21622 — Critical (CVSS 9.8): Insufficient Session Expiration vulnerability in hexpm hexpm/hexpm ('Elixir.Hexpm.Accounts.PasswordReset' module)…
CVE-2025-59786 — Critical (CVSS 9.8): 2N Access Commander version 3.4.2 and prior improperly invalidates session tokens, allowing multiple session cookies to…
CVE-2026-26342 — Critical (CVSS 9.8): Tattile Smart+, Vega, and Basic device families firmware versions 1.181.5 and prior implement an authentication token…
CVE-2026-1435 — Critical (CVSS 9.8): Not properly invalidated session vulnerability in Graylog Web Interface, version 2.2.3, due to incorrect management of…

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