RUSTSEC-2026-0209 AES-GCM did not enforce limits on AAD length
The library fails to enforce AAD length limits, allowing attackers to degrade authentication security in AES-GCM operations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is RUSTSEC-2026-0209?
RUSTSEC-2026-0209 is a vulnerability in libcrux-aesgcm, published on 9 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
NIST Special Publication 800-38D specifies that the bit length of the
AAD shall not exceed 2^64 - 1 bits. The implementation of AES-GCM in
libcrux-aesgcm neither enforced this limit for encryption nor for
decryption.
Impact
Use of AES-GCM with AAD of length exceeding the prescribed maximum length degrades the authentication security of the GCM tag.
Mitigation
Starting from version 0.0.9 (published as [email protected]),
limits on the length of the AAD input are enforced, so overlong AAD
inputs result in an error on encryption and decryption.
Which versions are affected by RUSTSEC-2026-0209?
1 open source package ship an affected version, including libcrux-aesgcm.
| Package | Affected | Fixed in |
|---|---|---|
libcrux-aesgcm crates.io | From 0.0.0-0 | None |
How do I fix RUSTSEC-2026-0209?
No fix has been published for RUSTSEC-2026-0209 yet. Limit exposure of the affected software until one is available.
Is RUSTSEC-2026-0209 being exploited?
There is no known exploitation of RUSTSEC-2026-0209 in the wild and no public exploit code.