High 8.7Published Apr 7, 2026

CVE-2026-34582Botan has a TLS 1.3 certificate authentication bypass

Updated under an hour ago (Oct 27, 2026, 4:10 AM ET)

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It affects randombit botan and 2 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for randombit botan

Exploited in the last 30 days

Botan is a C++ cryptography library. Prior to version 3.11.1, the TLS 1.3 implementation allowed ApplicationData records to be processed prior to the Finished message being received. A server which is attempting to enforce client authentication via certificates can by bypassed by a client which entirely omits Certificate, CertificateVerify, and the Finished message and instead sends application data records. This vulnerability is fixed in 3.11.1.

CVSS: 8.7 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Weakness (CWE): CWE-841, CWE-166
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Modified
Record last updated: Jul 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

randombit botan randombit:botan (from the name)	before 3.11.1	CNA record
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux	10	CISA ADP
botan_project botan botan_project:botan	from 3.0.0 through 3.11.0	NVD

References

References

https://github.com/randombit/botan/security/advisories/GHSA-pxcj-9ppx-g86g	x-refsource-confirm, mitigation, vendor-advisory
https://access.redhat.com/security/cve/CVE-2026-34582
https://bugzilla.redhat.com/show_bug.cgi?id=2456285
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34582.json

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.