# CVE-2026-15997 — Legion of the Bouncy Castle Inc. BC-LTS

> As of 2026-07-17, CVE-2026-15997 is a Low-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in Legion of the Bouncy Castle Inc. BC-LTS, CVSS v4.0 1.7, EPSS 0.1% (1.0th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-15997 as of 2026-07-17; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-07-17

## What is CVE-2026-15997?

Out-of-bounds write vulnerability in Legion of the Bouncy Castle Inc. BC-LTS bcprov-lts8on on ARM allows Overflow Buffers. This vulnerability is associated with program files https://github.Com/bcgit/bc-lts-java/blob/main/native_c/arm/sha/shake.C, https://github.Com/bcgit/bc-lts-java/blob/main/native_c/arm/sha/sha3.C. This issue affects BC-LTS: from 2.73.0 before 2.73.12.1. Issue is only applicable if application involved is accepting memoable SHA3 / SHAKE states from potentially untrusted sources.

The record classifies CVE-2026-15997 under weakness class [CWE-787](https://intel.threadlinqs.com/cwe/CWE-787). 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 81 days ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 1.7 — Low (derived from score) (`CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/S:P/AU:N/R:A/V:D/RE:M/U:Amber`)
- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 1.0% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 0.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-16, last modified 2026-07-17

## Is CVE-2026-15997 being exploited?

It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **Legion of the Bouncy Castle Inc.**: BC-LTS

## How to fix CVE-2026-15997

No vendor patch reference has been recorded for CVE-2026-15997 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-15997

No threat campaign in the Threadlinqs corpus currently references CVE-2026-15997, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-07-18. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [github.com](https://github.com/bcgit/bc-lts-java/wiki/CVE-2026-15997)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-15997
Full detection coverage and IOCs for threats exploiting CVE-2026-15997 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp