Pkcs11-provider: side-channel proofing pkcs#1 1.5 paths

published 2024-01-30 2 y ago modified 2026-06-17 4 mo ago also EUVD-2023-58503

cvss: 8.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits: 0; none known

A security vulnerability has been identified in the pkcs11-provider, which is associated with Public-Key Cryptography Standards (PKCS#11). If exploited successfully, this vulnerability could result in a Bleichenbacher-like security flaw, potentially enabling a side-channel attack on PKCS#1 1.5 decryption.

Patch / fix

distros 1 links 1

pkcs11-provider Debian 14, Debian 13 0.3-1

debian advisories DEBIAN-CVE-2023-6258

github.com/latchset/pkcs11-provider#308 pull request

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-6258 updated 2025-11-21 cvss 8.1

pkcs11-provider: Side-channel proofing PKCS#1 1.5 paths

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-01-31)

Exploit prediction

0.56% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

n/a pkcs11-provider
Fedora Fedora

Classification

Weakness

CWE-1300 Improper Protection of Physical Side Channels
CWE-203 Observable Discrepancy

References

github.com /latchset/pkcs11-provider/pull/308
issue-tracking, patch
bugzilla.redhat.com /show_bug.cgi?id=2251062
issue-tracking, third-party-advisory

Sources

CVE List CVE-2023-6258
NVD CVE-2023-6258

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary