This vulnerability (CVE-2026-40993) affects Spring Security versions 7.0.0 through 7.0.5. An attacker who has write permissions to the database table saml2_asserting_party_metadata managed by JdbcAssertingPartyMetadataRepository can store malicious serialized payloads in the verification_credentials and encryption_credentials columns. This deserialization of untrusted data (CWE-502) can lead to integrity and availability impacts. The CVSS 3.1 score is 7.3, indicating high severity, with attack vector requiring adjacent network access, high complexity, and high privileges. No official fix or patch is currently documented.

An attacker with write access to the affected database table can inject malicious serialized objects that may compromise the integrity and availability of the application using Spring Security. This could allow unauthorized manipulation or disruption of security credentials used for verification or encryption, potentially leading to denial of service or other integrity violations.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, restrict write access to the saml2_asserting_party_metadata database table to trusted users only to prevent injection of malicious serialized data.