How severe is CVE-2020-26542?

CVE-2020-26542 has a CVSS 3.x base score of 9.8, 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 high.

Is CVE-2020-26542 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-26542?

CVE-2020-26542 affects Percona Percona Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-26542?

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.

When was CVE-2020-26542 published?

CVE-2020-26542 was published on 2020-11-09 and last updated on 2026-06-17.

CVE-2020-26542

CVE-2020-26542 is a critical-severity vulnerability in Percona Percona Server with a CVSS 3.x base score of 9.8. 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-287.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Percona Percona Server
Published: 2020-11-09
Last modified: 2026-06-17

Description

An issue was discovered in the MongoDB Simple LDAP plugin through 2020-10-02 for Percona Server when using the SimpleLDAP authentication in conjunction with Microsoft’s Active Directory, Percona has discovered a flaw that would allow authentication to complete when passing a blank value for the account password, leading to access against the service integrated with which Active Directory is deployed at the level granted to the authenticating account.

Frequently asked questions

What is CVE-2020-26542?: An issue was discovered in the MongoDB Simple LDAP plugin through 2020-10-02 for Percona Server when using the SimpleLDAP authentication in conjunction with Microsoft’s Active Directory, Percona has discovered a flaw that would allow authentication to complete when passing a blank value for the account password, leading to access against the service integrated with which Active Directory is deployed at the level granted to the authenticating account.
How severe is CVE-2020-26542?: CVE-2020-26542 has a CVSS 3.x base score of 9.8, 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 high.
Is CVE-2020-26542 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-26542?: CVE-2020-26542 affects Percona Percona Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-26542?: 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.
When was CVE-2020-26542 published?: CVE-2020-26542 was published on 2020-11-09 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:percona:percona_server:*:*:*:*:*:mongodb:*:*

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