In Bouncy Castle for Java, before version 1.85, the BCFKS keystore loader honours the key‑derivation‑function cost value contained in an untrusted keystore file. Because the loader accepts the outlined cost from the file, loading a keystore that specifies a very high cost parameter can cause the library to perform extensive key‑derivation work. Based on the description, it is inferred that this can result in significant CPU consumption, potentially leading to a denial‑of‑service condition. This inference is not explicitly stated in the description, but follows logically from the stated behavior.

The vulnerability affects Bouncy Castle for Java products, including BC-JAVA before 1.85, BC-LTS-JAVA before 2.73.12, and Bouncy Castle for Java FIPS (BC‑FJA) before bc‑fips 1.0.2.7, 2.0.2 and 2.1.3. The affected vendors are the Legion of the Bouncy Castle Inc. for their BC‑FJA, BC‑JAVA, and BC‑LTS‑JAVA libraries.

The CVSS score of 5.3 indicates a moderate impact. EPSS data is not available, and the vulnerability is not listed in CISA KEV. Based on the description, it is inferred that the likely attack vector would be local or remote if an application allows a user to supply a keystore file, where an attacker could provide an untrusted file containing an extreme KDF cost to exhaust resources during loading. This inference is not explicitly stated in the description. No privileged escalation is required; the exploit simply triggers excessive CPU usage when the keystore is parsed.