PT-2026-40732 · Crates.Io · Libcrux-Chacha20Poly1305

Published 2026-03-29 · Updated 2026-03-29

OSV

CVSS v4.0

8.2

High

Base vector

AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

An application that passes in a ciphertext buffer of length greater than ptxt.len() + TAG LEN to libcrux chacha20poly1305::encrypt or libcrux chacha20poly1305::xchacha20 poly1305::encrypt would experience a panic.

Impact

An application where the length of the ciphertext buffer is under attacker control could be made to crash.

Mitigation

The fix makes it so that libcrux chacha20poly1305::encrypt and libcrux chacha20poly1305::xchacha20 poly1305::encrypt no longer panic in this case, but instead write out the ciphertext and tag into the first ptxt.len() + TAG LEN bytes of the provided buffer.

Fix

Related Identifiers

RUSTSEC-2026-0124

Affected Products

Libcrux-Chacha20Poly1305

References · 4

• https://osv.dev/vulnerability/RUSTSEC-2026-0124 · Vendor Advisory
• https://github.com/cryspen/libcrux/pull/1386 · Note
• https://crates.io/crates/libcrux-chacha20poly1305 · Note
• https://rustsec.org/advisories/RUSTSEC-2026-0124.html · Note