GHSA-pv9v-5j35-xwcr libcrux Panics During Standalone MAC Operations
Incorrect key length constant causes panics in standalone MAC operations, leading to denial of service for applications using libcrux-poly1305 directly.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-pv9v-5j35-xwcr?
GHSA-pv9v-5j35-xwcr is a denial of service vulnerability in libcrux-poly1305, published on 4 Mar 2026.
Official description
An incorrect constant for the key length in libcrux-poly1305 caused the standalone MAC function libcrux_poly1305::mac to always panic with an out-of-bounds memory access.
Impact
Applications wishing to use libcrux-poly1305 as a standalone MAC would experience panics. The use of libcrux-poly1305 in libcrux-chacha20poly1305 is unaffected.
Mitigation
Starting from version 0.0.5, the correct value is used for the key length constant.
Which versions are affected by GHSA-pv9v-5j35-xwcr?
3 open source packages ship an affected version, including libcrux-poly1305.
| Package | Affected | Fixed in |
|---|---|---|
libcrux-poly1305 crates.io | All versions | 0.0.5 |
libcrux-poly1305 crates.io | All versions | 0.0.5 |
libcrux-poly1305 crates.io | From 0.0.0-0 | 0.0.5 |
How do I fix GHSA-pv9v-5j35-xwcr?
Upgrade libcrux-poly1305 to 0.0.5 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is GHSA-pv9v-5j35-xwcr being exploited?
There is no known exploitation of GHSA-pv9v-5j35-xwcr in the wild and no public exploit code.
Sources
Also known as RUSTSEC-2026-0073.