🛡️ CVE-2021-36740 — varnish
Description
Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request. This affects Varnish Enterprise 6.0.x before 6.0.8r3, and Varnish Cache 5.x and 6.x before 6.5.2, 6.6.x before 6.6.1, and 6.0 LTS before 6.0.8.
Affected software
CVE-2021-36740 is recorded against 1 package.
- varnish
Timeline and source
Published on 6 March 2024 and last revised on 3 April 2025. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
docs.varnish-software.com (Web)
github.com (Web)
github.com (Web)
lists.fedoraproject.org (Web)
lists.fedoraproject.org (Web)
varnish-cache.org (Web)
www.debian.org (Web)
nvd.nist.gov (Web)
CVE-2021-36740 on other distributions
Each distribution ships its own build and its own fixed version. Pick the one you run:
Details
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| varnish | — | — |
References
Similar Threats
- Unknown ALPINE-CVE-2025-8671
- Unknown ALSA-2025:8550
- Unknown ALSA-2025:8336
- Unknown ALSA-2025:8337
- Unknown ALPINE-CVE-2025-47905
More CVE 2021 advisories
Browse all of CVE 2021 in the advisory index.
Vulnerability Monitoring
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