CVE-2026-26080
HAProxy Varint Handling Denial of Service Vulnerability
Description
HAProxy Community Edition 3.2.x through 3.3.x before 3.3.3 can enter a loop or crash because varint is mishandled. HAProxy Enterprise and ALOHA are also affected.
INFO
Published Date :
July 20, 2026, 4:16 p.m.
Last Modified :
Aug. 25, 2026, 3:43 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-26080
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | LOW | 8254265b-2729-46b6-b9e3-3dfca2d5bfca | ||||
| CVSS 3.1 | LOW | [email protected] |
Solution
- Update HAProxy to version 3.3.3 or later.
- Apply vendor patches for affected versions.
- Restart HAProxy service after update.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-26080.
| URL | Resource |
|---|---|
| https://git.haproxy.org/?p=haproxy-3.2.git;a=commit;h=5bb098ce8a656ec5711b4de3e4c87f12b216e7a1 | Patch Vendor Advisory |
| https://www.haproxy.org | Product |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-26080 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-26080
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-26080 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-26080 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Aug. 25, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:* versions from (including) 3.2 up to (excluding) 3.2.12 *cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:* versions from (including) 3.3 up to (excluding) 3.3.3 Added CPE Configuration OR *cpe:2.3:a:haproxy:aloha:*:*:*:*:*:*:*:* versions from (including) 17.0.0 up to (excluding) 17.0.18 *cpe:2.3:a:haproxy:aloha:*:*:*:*:*:*:*:* versions from (including) 17.5.0 up to (excluding) 17.5.16 Added CPE Configuration OR *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-353.334:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-353.336:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-353.347:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-353.355:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-353.376:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-353.385:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-353.398:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-354.402:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-354.439:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-358.439:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-359.440:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-360.460:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-362.473:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-363.476:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-363.478:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-363.498:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-363.511:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-365.529:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-365.531:*:*:*:*:*:* *cpe:2.3:a:haproxy:haproxy_enterprise:3.2r1:1.0.0-365.545:*:*:*:*:*:* Added Reference Type MITRE: https://git.haproxy.org/?p=haproxy-3.2.git;a=commit;h=5bb098ce8a656ec5711b4de3e4c87f12b216e7a1 Types: Patch, Vendor Advisory Added Reference Type MITRE: https://www.haproxy.org Types: Product -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 20, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-26080', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-20T18:16:29.299899Z'} -
New CVE Received by [email protected]
Jul. 20, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'HAProxy', 'product': 'HAProxy', 'versions': [{'status': 'affected', 'version': '3.2', 'lessThan': '3.2.12', 'versionType': 'custom'}, {'status': 'affected', 'version': '3.3', 'lessThan': '3.3.3', 'versionType': 'custom'}], 'defaultStatus': 'unaffected'}] Added Description HAProxy Community Edition 3.2.x through 3.3.x before 3.3.3 can enter a loop or crash because varint is mishandled. HAProxy Enterprise and ALOHA are also affected. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-252 Added Reference https://git.haproxy.org/?p=haproxy-3.2.git;a=commit;h=5bb098ce8a656ec5711b4de3e4c87f12b216e7a1 Added Reference https://www.haproxy.org