Resource exhaustion in Bouncycastle Bc-Java

CVE-2026-58063

In Bouncy Castle for Java before 1.85, BCFKS keystore load honours unbounded KDF cost from untrusted file. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 1.0.2.7 (1.0.X series), 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.004 (36.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-58063: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-58063?
CVE-2026-58063 is a medium-severity vulnerability in Bouncycastle Bc-Java, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.3/10. Published 2026-08-03.
How severe is CVE-2026-58063?
Medium severity. CVSS v3 base score is 5.3 out of 10.