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CVE-2022-23959

31
FAUCET Score

CVE-2022-23959 is a critical request smuggling vulnerability (CWE-444) affecting Varnish Cache versions prior to 6.6.2, 7.0.2, 6.0.10, and specific Varnish Enterprise versions. This vulnerability allows attackers to manipulate HTTP/1 connections, potentially leading to unauthorized access to sensitive information (C) and data integrity compromise (I). With a CVSS score of 9.1 (CRITICAL), it is easily exploitable over the network with low attack complexity and no user interaction required. While there is no evidence of active exploitation, public exploit code, or Metasploit/Nuclei modules, the vulnerability has garnered significant community discussion, indicating awareness among security researchers.

Impacted Technologies

VendorProductVersion(s)CPE
>= 1.0.0, < 6.6.2CPE matchmatch criteria
cpe:2.3:a:varnish-software:varnich_cache:*:*:*:*:-:*:*:*
>= 4.1.1, < 4.1.11r6CPE matchmatch criteria
cpe:2.3:a:varnish-software:varnich_cache:*:*:*:*:plus:*:*:*
4.1CPE matchmatch criteria
cpe:2.3:a:varnish-software:varnich_cache:4.1:*:*:*:lts:*:*:*
>= 6.0.0, < 6.0.10CPE matchmatch criteria
cpe:2.3:a:varnish-software:varnish_cache:*:*:*:*:lts:*:*:*
>= 6.0.0, < 6.0.9r4CPE matchmatch criteria
cpe:2.3:a:varnish-software:varnish_cache_plus:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

9.1CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
Exploitability Score
3.9
Impact Score
5.2
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.97%
Probability of exploitation in next 30 days
EPSS Percentile
78.3%
Percentile rank of EPSS score among Peer Group
As of 2026-07-25
Model: v2026.06.15
This CVE's current EPSS score of 0.0197 is in the 67th percentile among its peer group of 36,829 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (5)

redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: varnish:6-8050020220201171716.c5368500
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.1 Update Services for SAP SolutionsFixed in: varnish:6-8010020220201182846.c27ad7f8
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.2 Extended Update SupportFixed in: varnish:6-8020020220201181211.4cda2c84
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.4 Extended Update SupportFixed in: varnish:6-8040020220201180030.522a0ee4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-varnish6-varnish-0:6.0.8-2.el7.1
View patch

Vendor Advisories (1)

redhatCVE-2022-23959Important

varnish: HTTP/1 request smuggling vulnerability

Jan 25, 2022

References

docs.varnish-software.com / security/VSV00008
MitigationVendor Advisory
lists.debian.org / debian-lts-announce/2022/02/msg00014.html
Mailing ListThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/UMMDMQWNAE3BTSZUHXQHVAMZC5TLHLYT
varnish-cache.org / security/VSV00008.html
MitigationVendor Advisory
debian.org / security/2022/dsa-5088
Third Party Advisory