Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2023-0836

23
FAUCET Score

CVE-2023-0836 is an information leak vulnerability affecting HAProxy versions 2.1 through 2.7.1 (excluding patched versions). This flaw stems from 5 uninitialized bytes in the connection buffer during FCGI_BEGIN_REQUEST record encoding, potentially disclosing sensitive data to FastCGI backends. With a CVSS score of 7.5 (HIGH), it is a network-exploitable vulnerability with low attack complexity and high confidentiality impact, requiring no user interaction or privileges. There is currently no evidence of active exploitation, public exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
>= 2.2.0, < 2.2.27CPE matchmatch criteria
cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*
>= 2.4.0, <= 2.4.21CPE matchmatch criteria
cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*
>= 2.5.0, <= 2.5.11CPE matchmatch criteria
cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*
>= 2.6.0, <= 2.6.8CPE matchmatch criteria
cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*
2.1.0CPE matchmatch criteria
cpe:2.3:a:haproxy:haproxy:2.1.0:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.20%
Probability of exploitation in next 30 days
EPSS Percentile
65.0%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0120 is in the 44th percentile among its peer group of 51,553 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (4)

redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 9Fixed in: haproxy-0:2.4.22-1.el9
View patch
redhatno patchvia redhat_api
Product: Red Hat Ceph Storage 5Fixed in: haproxy
redhatend of lifevia redhat_api
Product: Red Hat OpenShift Container Platform 4Fixed in: haproxy
redhatend of lifevia redhat_api
Product: Red Hat Software CollectionsFixed in: rh-haproxy18-haproxy

Vendor Advisories (1)

redhatCVE-2023-0836Moderate

haproxy: data leak via fcgi requests

Dec 9, 2022

References

git.haproxy.org
debian.org / security/2023/dsa-5388