CVE-2023-0836

HIGH
7.5
CVSS Score
Published: March 29, 2023 at 12:00 AM UTC
Updated: June 17, 2026 at 05:26 AM UTC
1 product affected across 1 vendorHAProxy

Using HAProxy by N/A?

Get instant alerts when new vulnerabilities affect HAProxy - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.5
Exploit prediction
EPSS 1%
SSVC
No known exploit

Description

An information leak vulnerability was discovered in HAProxy 2.1, 2.2 before 2.2.27, 2.3, 2.4 before 2.4.21, 2.5 before 2.5.11, 2.6 before 2.6.8, 2.7 before 2.7.1. There are 5 bytes left uninitialized in the connection buffer when encoding the FCGI_BEGIN_REQUEST record. Sensitive data may be disclosed to configured FastCGI backends in an unexpected way.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.2.0 ≤ v < 2.2.272.4.0 ≤ v ≤ 2.4.212.5.0 ≤ v ≤ 2.5.112.6.0 ≤ v ≤ 2.6.82.1.02.2.272.3.02.4.212.5.112.6.82.7.02.7.12.8
Affected range stops below 2.2.27, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-200CWE-459

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card