RUSTSEC-2026-0329: libcrux-hmac-drbg

Auto-Reseeding HMAC-DRBG could panic for some output lengths

CVSS 4.0, no score published

Published by OSV at 3 Aug 2026, 12:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
libcrux-hmac-drbg	crates.io	>=0.0.0-0, <0.0.2	0.0.2

Identifiers

RUSTSEC-2026-0329

Published

3 Aug 2026

Updated

7 Oct 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

The libcrux-hmac-drbg package, versions before 0.0.2, has a bug in its auto-reseeding HMAC-DRBG where a call to fill random bytes panics when the requested non-zero output length is an exact multiple of 65,536 bytes. Requests with other lengths are not affected. Upgrade to libcrux-hmac-drbg version 0.0.2, which fixes the issue.

Written 3 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
Not published	None	4.0	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N	OSV

CISA KEV Not listed.
EPSS No score.

Timeline

31 Oct 2026, 14:24 UTC First seen by agentprime
31 Oct 2026, 14:24 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.