Varnishcacheproject Varnish Cache

Varnish Cache before 7.6.2 Desync via HTTP/1.0+ fixed in 7.6.2
CVE-2025-30346 4.8 - Medium - March 21, 2025

Varnish Cache before 7.6.2 and Varnish Enterprise before 6.0.13r10 allow client-side desync via HTTP/1 requests.

HTTP Request Smuggling

HTTP/2 DoS via Stream Reset in nginx
CVE-2023-44487 7.5 - High - October 10, 2023

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

Resource Exhaustion

Varnish Cache HTTP Request Forgery via HTTP/2 Pseudo-Headers (7.2.1)
CVE-2022-45060 7.5 - High - November 09, 2022

An HTTP Request Forgery issue was discovered in Varnish Cache 5.x and 6.x before 6.0.11, 7.x before 7.1.2, and 7.2.x before 7.2.1. An attacker may introduce characters through HTTP/2 pseudo-headers that are invalid in the context of an HTTP/1 request line, causing the Varnish server to produce invalid HTTP/1 requests to the backend. This could, in turn, be used to exploit vulnerabilities in a server behind the Varnish server. Note: the 6.0.x LTS series (before 6.0.11) is affected.

Varnish Cache 7.x (7.1.1/7.2.0) Hop-by-Hop Header Request Smuggling
CVE-2022-45059 7.5 - High - November 09, 2022

An issue was discovered in Varnish Cache 7.x before 7.1.2 and 7.2.x before 7.2.1. A request smuggling attack can be performed on Varnish Cache servers by requesting that certain headers are made hop-by-hop, preventing the Varnish Cache servers from forwarding critical headers to the backend.

HTTP Request Smuggling

Varnish Cache 7.0.07.1.0: Forced Restart via Forged HTTP Backend Response
CVE-2022-38150 6.5 - Medium - August 11, 2022

In Varnish Cache 7.0.0, 7.0.1, 7.0.2, and 7.1.0, it is possible to cause the Varnish Server to assert and automatically restart through forged HTTP/1 backend responses. An attack uses a crafted reason phrase of the backend response status line. This is fixed in 7.0.3 and 7.1.1.

Resource Exhaustion

In Varnish Cache before 6.6.2 and 7.x before 7.0.2, Varnish Cache 6.0 LTS before 6.0.10, and and Varnish Enterprise (Cache Plus) 4.1.x before 4.1.11r6 and 6.0.x before 6.0.9r4, request smuggling
CVE-2022-23959 9.1 - Critical - January 26, 2022

In Varnish Cache before 6.6.2 and 7.x before 7.0.2, Varnish Cache 6.0 LTS before 6.0.10, and and Varnish Enterprise (Cache Plus) 4.1.x before 4.1.11r6 and 6.0.x before 6.0.9r4, request smuggling can occur for HTTP/1 connections.

HTTP Request Smuggling

Varnish Cache, with HTTP/2 enabled
CVE-2021-36740 6.5 - Medium - July 14, 2021

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.

HTTP Request Smuggling

Varnish HTTP cache before 3.0.4: ACL bug
CVE-2013-4090 - February 12, 2020

Varnish HTTP cache before 3.0.4: ACL bug

An issue was discovered in Varnish Cache before 6.0.4 LTS, and 6.1.x and 6.2.x before 6.2.1
CVE-2019-15892 7.5 - High - September 03, 2019

An issue was discovered in Varnish Cache before 6.0.4 LTS, and 6.1.x and 6.2.x before 6.2.1. An HTTP/1 parsing failure allows a remote attacker to trigger an assert by sending crafted HTTP/1 requests. The assert will cause an automatic restart with a clean cache, which makes it a Denial of Service attack.

assertion failure

vbf_stp_error in bin/varnishd/cache/cache_fetch.c in Varnish HTTP Cache 4.1.x before 4.1.9 and 5.x before 5.2.1
CVE-2017-8807 - November 16, 2017

vbf_stp_error in bin/varnishd/cache/cache_fetch.c in Varnish HTTP Cache 4.1.x before 4.1.9 and 5.x before 5.2.1 allows remote attackers to obtain sensitive information from process memory because a VFP_GetStorage buffer is larger than intended in certain circumstances involving -sfile Stevedore transient objects.

An issue was discovered in Varnish HTTP Cache 4.0.1 through 4.0.4, 4.1.0 through 4.1.7, 5.0.0, and 5.1.0 through 5.1.2
CVE-2017-12425 - August 04, 2017

An issue was discovered in Varnish HTTP Cache 4.0.1 through 4.0.4, 4.1.0 through 4.1.7, 5.0.0, and 5.1.0 through 5.1.2. A wrong if statement in the varnishd source code means that particular invalid requests from the client can trigger an assert, related to an Integer Overflow. This causes the varnishd worker process to abort and restart, losing the cached contents in the process. An attacker can therefore crash the varnishd worker process on demand and effectively keep it from serving content - a Denial-of-Service attack. The specific source-code filename containing the incorrect statement varies across releases.

Varnish 3.x before 3.0.7, when used in certain stacked installations
CVE-2015-8852 - April 25, 2016

Varnish 3.x before 3.0.7, when used in certain stacked installations, allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via a header line terminated by a \r (carriage return) character in conjunction with multiple Content-Length headers in an HTTP request.

varnish 3.0.3 uses world-readable permissions for the /var/log/varnish/ directory and the log files in the directory, which
CVE-2013-0345 - May 08, 2014

varnish 3.0.3 uses world-readable permissions for the /var/log/varnish/ directory and the log files in the directory, which allows local users to obtain sensitive information by reading the files. NOTE: some of these details are obtained from third party information.

Varnish before 3.0.5
CVE-2013-4484 - November 01, 2013

Varnish before 3.0.5 allows remote attackers to cause a denial of service (child-process crash and temporary caching outage) via a GET request with trailing whitespace characters and no URI.

Buffer Overflow