CVE-2026-119559

Description

OpenLiteSpeed through 1.9.4 contains an authentication bypass vulnerability that allows unauthenticated remote attackers to evade virtual host client certificate requirements over HTTP/3. Because QuicStream inherits a verifyContext() implementation that always returns true, attackers can present a non-mTLS host's SNI with a protected Host header to access protected content.

Metrics

CVSS 3.1

5.9 (MEDIUM) Score source: NVD CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS 4.0

8.2 (HIGH) Score source: CNA CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — exploit probability

0% (percentile: 22) as of 1 November 2026

CWE

CWE-295

References

• https://abraxaslabs.tech/research/openlitespeed-h3-mtls-verifycontext
• https://github.com/litespeedtech/openlitespeed
• https://github.com/litespeedtech/openlitespeed/blob/v1.9.4/src/http/httpsession…
• https://github.com/litespeedtech/openlitespeed/blob/v1.9.4/src/quic/quicstream.…
• https://github.com/litespeedtech/openlitespeed/blob/v1.9.4/src/sslpp/hiocrypto.…
• https://www.vulncheck.com/advisories/openlitespeed-through-1.9.4-mtls-bypass-vi…