CVE-2026-58063: Legion of the Bouncy Castle BC-JAVA · Unthrottled Resource Allocation
Affects Legion of the Bouncy Castle BC-JAVASource CVE Database V5
Not known to be exploited · CVSS 5.3 Medium : upgrade to 1.85 when convenient.
Data as of 26 Oct 2026, 12:29 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 36% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-08-03.
- Patch
- Available – fixed in 1.85, 2.73.12, 2.1.3 +2
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/U:AmberExploitation evidence
Disclosed: evidence found.
CVE published 3 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade BC-JAVA and Legion of the Bouncy Castle Inc./bcprov to 1.85; BC-LTS-JAVA and Legion of the Bouncy Castle Inc./bcprov-lts8on to 2.73.12; BC-FJA and Legion of the Bouncy Castle Inc./bc-fips to 2.1.3, 2.0.2 or 1.0.2.7.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Legion of the Bouncy Castle Inc.BC-JAVA | Affected
| Fixed in
|
| Legion of the Bouncy Castle Inc.BC-LTS-JAVA | Affected
| Fixed in
|
| Legion of the Bouncy Castle Inc.BC-FJA | Affected
| Fixed in
|
| Legion of the Bouncy Castle Inc.BC-FJA | Affected
| Fixed in
|
| Legion of the Bouncy Castle Inc.BC-FJA | Affected
| Fixed in
|
MavenLegion of the Bouncy Castle Inc./bcprovpkg:maven/Legion of the Bouncy Castle Inc./bcprovOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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).