Out-of-bounds read in Botan - CVE-2026-32877
Published: April 8, 2026
Vulnerability identifier: #VU125381
CSH Severity: High
CVSS v4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-32877
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service and disclose sensitive information.
The vulnerability exists due to out-of-bounds read in the SM2 decryption authentication code value (C3) check when processing a crafted SM2 ciphertext with an undersized C3 hash field. A remote attacker can send a specially crafted SM2 ciphertext to cause a denial of service and disclose sensitive information.
The over-read is limited to up to 31 bytes and may result in other undefined behavior.
Affected software
Botan
Fedora
botan3
Fedora
botan3
How to mitigate CVE-2026-32877
Install security update from vendor's website.
Botan - update to 3.11.0
botan3 - addressed in versions 3.9.0-3.el10_3, 3.9.0-4.el10_3, 3.9.0-6.fc44, 3.9.0-7.fc44
botan3 - addressed in versions 3.9.0-3.el10_3, 3.9.0-4.el10_3, 3.9.0-6.fc44, 3.9.0-7.fc44