Improper Verification of Cryptographic Signature in scapy - #VU148425
Published: September 9, 2026
Vulnerability identifier: #VU148425
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose client application data.
The vulnerability exists due to improper verification of cryptographic signatures in TLSCertificateVerify.post_dissection() and TLSClientAutomaton when processing a TLS 1.3 server CertificateVerify message. A remote attacker can present a certificate with an invalid CertificateVerify signature to disclose client application data.
The TLS client continues the handshake and sends caller-supplied data despite the failed server-authentication proof.
Affected software
scapy
Remediation
Install security update from vendor's website.
scapy - update to 2.8.0