How severe is CVE-2025-9340?

No CVSS score has been assigned to CVE-2025-9340 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-9340?

CVE-2025-9340 affects the following packages: org.bouncycastle:bc-fips (Maven). Ecosystems affected: Maven.

How do I fix CVE-2025-9340?

Update org.bouncycastle:bc-fips to 2.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-9340 is resolved across your whole dependency graph.

How do I detect CVE-2025-9340 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.bouncycastle:bc-fips, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-9340 if there is no patch (or I can't update yet)?

Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Is CVE-2025-9340 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-9340 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-9340?

CVE-2025-9340 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 7th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2025-9340?

CVE-2025-9340 is classified as Out-of-bounds Write (CWE-787). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-9340 published, and has it been updated?

CVE-2025-9340 was published on August 22, 2025 and was last updated on August 22, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2025-9340: bc-fips Memory Corruption

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-9340.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs7th percentile — riskier than 7% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

☕org.bouncycastle:bc-fips

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Out-of-bounds Write vulnerability in Legion of the Bouncy Castle Inc. Bouncy Castle for Java bc-fips on All (API modules). This vulnerability is associated with program files org/bouncycastle/jcajce/provider/BaseCipher.

This issue affects Bouncy Castle for Java: from BC-FJA 2.1.0 through 2.1.0.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.bouncycastle:bc-fips`	≥ 2.1.0&&< 2.1.1	2.1.1`org.bouncycastle:bc-fips:2.1.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.bouncycastle:bc-fips, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.bouncycastle:bc-fips to 2.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-9340 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Frequently Asked Questions

Out-of-bounds Write vulnerability in Legion of the Bouncy Castle Inc. Bouncy Castle for Java bc-fips on All (API modules). This vulnerability is associated with program files org/bouncycastle/jcajce/provider/BaseCipher. This issue affects Bouncy Castle for Java: from BC-FJA 2.1.0 through 2.1.0.

O3 Security · Impact-Aware SCA

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CVE-2025-9340 — bc-fips