Reported

February 11, 2026

Issued

March 24, 2026

Package

hpke-rs (crates.io)

Type

Vulnerability

Aliases

• GHSA-g433-pq76-6cmf

References

• https://github.com/cryspen/hpke-rs/pull/128

CVSS Score

8.2 HIGH

CVSS Details

Attack Complexity

Low

Attack Requirements

Present

Attack Vector

Network

Privileges Required

None

Availability Impact to the Subsequent System

None

Confidentiality Impact to the Subsequent System

None

Integrity Impact to the Subsequent System

None

User Interaction

None

Availability Impact to the Vulnerable System

High

Confidentiality Impact to the Vulnerable System

None

Integrity Impact to the Vulnerable System

None

CVSS Vector

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

Patched

• >=0.6.0

Affected Functions

Version

hpke_rs::Context::open

• <=0.5.0

hpke_rs::Context::seal

• <=0.5.0

Description

Constructing an HPKE Context with the AEAD algorithm set to HpkeExport resulted in a panic when calling Context::seal, or Context::open. This was due to an underflowing integer subtraction when calculating the length of a vector allocation for the AEAD nonce, which would panic on its own in debug mode and cause out-of-memory abort on the allocation in release mode.

Impact

Applications that could be made to use an HPKE context configured with HpkeExport as AEAD algorithm to open or seal a ciphertext would crash. Other applications are unaffected.

Mitigation

Starting with version 0.6.0, an error will be returned when attempting to call Context::seal or Context::open on an HPKE context with HpkeExport as AEADAlgorithm.

Advisory available under CC0-1.0 license.