CVE-2026-15997

Native ARM SHA3 / SHAKE `restoreFullState` fails to detect size_t underflow in a crafted encoded state

Assigner: bcorg
Reserved: 16.07.2026 Published: 16.07.2026 Updated: 17.07.2026

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.

Metrics

CVSS Vector: 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
CVSS Score: 1.7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	High	Confidentiality	None
Attack Complexity	High	Integrity	None	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	Active

CVSS 4.0

Product Status

Vendor	Legion of the Bouncy Castle Inc.
Product	BC-LTS
Versions	Default: unaffected affected from 2.73.0 to 2.73.12.1 (excl.)

Vendor

Legion of the Bouncy Castle Inc.

Product

BC-LTS

Versions

Default: unaffected

affected from 2.73.0 to 2.73.12.1 (excl.)

References

Problem Types

CWE-787 Out-of-bounds write CWE

Impacts