CVE-2026-85216

CVE-2026-85216 is a critical-severity vulnerability in Misp-project Misp 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-521.

Key facts

Description

MISP contains an authentication bypass vulnerability in its LDAP and LinOTP authentication components due to insufficient validation of user-supplied credentials. The custom LdapAuthenticate and LinOTPAuthenticate components replace CakePHP's FormAuthenticate implementation but did not replicate its credential validation checks. As a result, empty or non-string values could reach the underlying authentication mechanisms. In the LDAP authentication path, an attacker able to identify a valid directory user's email address could submit an empty password. The empty credential could be passed to ldap_bind(), where an LDAP server accepting unauthenticated binds may return a successful result for a valid distinguished name combined with an empty password. MISP could consequently treat the attacker as the corresponding authenticated directory user without verification of the user's password. The issue also affected the LinOTP authentication component. Invalid credential types were not rejected before being processed, and when mixed authentication was enabled, an empty password could be checked against a locally stored MISP password hash. LDAP-provisioned MISP accounts could additionally be created with an empty local password because account creation skipped normal validation, resulting in a hash corresponding to an empty password. This could permit authentication through the local fallback mechanism when such an account was no longer resolved through LDAP. Successful exploitation could allow a remote unauthenticated attacker to impersonate an existing MISP user. If the targeted account has administrative or other privileged permissions, the attacker could gain corresponding access to sensitive threat-intelligence data, modify or delete information, alter configuration, or perform other privileged operations. The patch resolves the vulnerability by requiring authentication identifiers and passwords to be valid strings, rejecting empty passwords where they are not explicitly permitted, and assigning a randomly generated local password to LDAP-provisioned accounts instead of storing a hash derived from an empty password.

Frequently asked questions

What is CVE-2026-85216?
MISP contains an authentication bypass vulnerability in its LDAP and LinOTP authentication components due to insufficient validation of user-supplied credentials. The custom LdapAuthenticate and LinOTPAuthenticate components replace CakePHP's FormAuthenticate implementation but did not replicate its credential validation checks. As a result, empty or non-string values could reach the underlying authentication mechanisms. In the LDAP authentication path, an attacker able to identify a valid directory user's email address could submit an empty password. The empty credential could be passed to ldap_bind(), where an LDAP server accepting unauthenticated binds may return a successful result for a valid distinguished name combined with an empty password. MISP could consequently treat the attacker as the corresponding authenticated directory user without verification of the user's password. The issue also affected the LinOTP authentication component. Invalid credential types were not rejected before being processed, and when mixed authentication was enabled, an empty password could be checked against a locally stored MISP password hash. LDAP-provisioned MISP accounts could additionally be created with an empty local password because account creation skipped normal validation, resulting in a hash corresponding to an empty password. This could permit authentication through the local fallback mechanism when such an account was no longer resolved through LDAP. Successful exploitation could allow a remote unauthenticated attacker to impersonate an existing MISP user. If the targeted account has administrative or other privileged permissions, the attacker could gain corresponding access to sensitive threat-intelligence data, modify or delete information, alter configuration, or perform other privileged operations. The patch resolves the vulnerability by requiring authentication identifiers and passwords to be valid strings, rejecting empty passwords where they are not explicitly permitted, and assigning a randomly generated local password to LDAP-provisioned accounts instead of storing a hash derived from an empty password.
How severe is CVE-2026-85216?
CVE-2026-85216 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-2026-85216 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-85216?
CVE-2026-85216 affects Misp-project Misp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-85216?
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-2026-85216 published?
CVE-2026-85216 was published on 2026-09-03 and last updated on 2026-09-10.

References

Affected products (1)

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