CVE-2026-15055 PKCS#8 / PBES2 decryptors honour unbounded KDF cost from input
Attackers can cause denial of service by providing crafted PKCS#8/PBES2 data with unbounded KDF costs, affecting Bouncy Castle Java libraries.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-15055?
CVE-2026-15055 is a medium-severity denial of service vulnerability in Bouncycastle Bc-Java, published on 3 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
In Bouncy Castle for Java before 1.85, PKCS#8 / PBES2 decryptors honour unbounded KDF cost from input. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).
Weakness: CWE-770
Which versions are affected by CVE-2026-15055?
It affects 3 products.
Products include Bouncycastle Bc-Java, Bouncycastle Bcpkix-Fips, Bouncycastle Bouncy Castle for Java Lts.
How do I fix CVE-2026-15055?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-15055 being exploited?
There is no known exploitation of CVE-2026-15055 in the wild and no public exploit code.
Other vulnerabilities in Bouncycastle Bc-Java
- CVE-2007-6721 Legion of the Bouncy Castle Java Cryptography API Bleichenbacher Oracle Vulnerability
- CVE-2018-1000613 Deserialization of Untrusted Data in Bouncy castle
- CVE-2026-58062 Stapled OCSP response accepted without binding to the checked certificate
- CVE-2026-59638 JSSE hostname verifier CN-fallback enabled by default despite documented opt-in
- CVE-2026-59650 MTI/A0 DH agreement exponentiates unvalidated peer value
Sources
Also known as CLEANSTART-2026-EJ43845, CLEANSTART-2026-IS00245, CLEANSTART-2026-QK31261, CLEANSTART-2026-YB90925, CLEANSTART-2026-YS76548, DEBIAN-CVE-2026-15055 and 2 more.