CVE-2026-119559
OpenLiteSpeed through 1.9.4 mTLS Bypass via HTTP/3 SNI and Host Mismatch
CVE-2026-119559 is a high vulnerability (CVSS 8.2) in Litespeed Technologies Openlitespeed, published October 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.29%, the 21st percentile. No source names a fixed version.
- Severity
- 8.2 HighCVSS 4.0, CVE List
- Exploit chance
- 0.29%EPSS, 21st percentile
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
- No fix listedNo source names one
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
Affected products
What each source reports
CVE List Score used
OpenLiteSpeed through 1.9.4 mTLS Bypass via HTTP/3 SNI and Host Mismatch
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.
- Record
CVE-2026-119559- CVSS 4.0
- 8.2 High
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 - CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-295
- Updated
- 2026-11-05
EUVDEUVD-2026-113824
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.
- Record
EUVD-2026-113824- CVSS 4.0
- 8.2 High
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 - Updated
- 2026-11-05
GitHub AdvisoriesGHSA-75rw-wm76-93p4
OpenLiteSpeed through 1.9.4 contains an authentication bypass vulnerability that allows...
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.
- Record
GHSA-75rw-wm76-93p4- CVSS 4.0
- 8.2 High
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 - CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-119559- CVSS 4.0
- 8.2 High
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 - CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-295
- Updated
- 2026-11-05
OSV
OpenLiteSpeed through 1.9.4 mTLS Bypass via HTTP/3 SNI and Host Mismatch
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.
- Record
CVE-2026-119559- CVSS 4.0
- 8.2 High
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 - Weakness
- CWE-295
- Updated
- 2026-11-07
History
| Recorded | Changed | Sources |
|---|---|---|
| facts, references | CVE List | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
References
github.com/litespeedtech/openlitespeed/blob/v1.9.4/src/http/httpsession.cpp
abraxaslabs.tech/research/openlitespeed-h3-mtls-verifycontext
vulncheck.com/advisories/openlitespeed-through-1.9.4-mtls-bypass-via-http-3-sni-and-host-mismatch
nvd.nist.gov/vuln/detail/CVE-2026-119559