A security advisory has been issued for Gentoo Linux, warning users about a vulnerability in the librnp package due to weak random number generation that can be easily cracked. The affected version of librnp, 0.18.0, generates weak session keys for public key encryption, potentially allowing attackers with just the public key to read encrypted messages. Users are advised to upgrade to the latest version of librnp (0.18.1 or higher) as soon as possible and be aware that sensitive information sent using affected software may have been compromised.

[ GLSA 202511-07 ] librnp: Weak random number generation

[ GLSA 202511-07 ] librnp: Weak random number generation

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Gentoo Linux Security Advisory GLSA 202511-07
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https://security.gentoo.org/
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Severity: High
Title: librnp: Weak random number generation
Date: November 26, 2025
Bugs: #966299
ID: 202511-07

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Synopsis
========

librnp uses weak random number generation such that generated keys can
be easily cracked.

Background
==========

librnp is a high performance C++ OpenPGP library.

Affected packages
=================

Package Vulnerable Unaffected
--------------- ------------ ------------
dev-util/librnp = 0.18.0 >= 0.18.1

Description
===========

The affected librnp version generated weak session keys for its public
key encryption (PKESK) mode.

Impact
======

Messages encrypted using the affected librnp version might be readable
by an attacker with just the public key.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All librnp users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-util/librnp-0.18.1"

If sensitive information was sent using e.g. Thunderbird (with
USE=system-librnp, the default), it should be considered potentially
viewable by an attacker.

References
==========

[ 1 ] CVE-2025-13470
https://nvd.nist.gov/vuln/detail/CVE-2025-13470

Availability
============

This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

https://security.gentoo.org/glsa/202511-07

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users' machines is of utmost
importance to us. Any security concerns should be addressed to
security@gentoo.org or alternatively, you may file a bug at
https://bugs.gentoo.org.

License
=======

Copyright 2025 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

https://creativecommons.org/licenses/by-sa/2.5