Native ARM SHA3 / SHAKE `restoreFullState` fails to detect size_t underflow in a crafted encoded state
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Active
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Legion of the Bouncy Castle Inc. | BC-LTS | 2.73.0 to before 2.73.12.1 | 2.73.12.1 | Patch available | CNA |
- BC-LTS VendorLegion of the Bouncy Castle Inc. Affected 2.73.0 to before 2.73.12.1 Fixed in 2.73.12.1 Patch available CNA
Remediation
- Fix · CNA BC-LTS (Legion of the Bouncy Castle Inc.) Fixed in 2.73.12.1
Timeline
- 2026-10-02 Threatist record created from CVE-2026-15997
- 2026-10-03 Alias added: GHSA-hcmw-xv23-7hqq
References
More Legion of the Bouncy Castle Inc. vulnerabilities
- TI-2018-15967 Legion of the Bouncy Castle Legion of the Bouncy Castle Java Cryptography APIs 1.58 up to… CVSS 3.1CRITICAL 9.8
- TI-2017-09736 BouncyCastle JCE TLS Bleichenbacher/ROBOT CVSS 3.0HIGH 7.5
- TI-2026-42545 MTI/A0 DH agreement exponentiates unvalidated peer value CVSS 4.0CRITICAL 9.3
- TI-2026-42533 JSSE hostname verifier CN-fallback enabled by default despite documented opt-in CVSS 4.0CRITICAL 9.3
- TI-2026-41816 Stapled OCSP response accepted without binding to the checked certificate CVSS 4.0CRITICAL 9.3
- TI-2026-07701 Name Constraints bypass via trailing dot in rfc822Name and URI CVSS 4.0CRITICAL 9.3
Sources
- CVE-2026-15997 · CVE Program
- CVE-2026-15997 · NVD
- FIRST EPSS
- GHSA-hcmw-xv23-7hqq · GitHub Advisory Database · CC BY 4.0
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