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Vulnerability record · CVE-2026-26080 · published 20 July 2026

CVE-2026-26080: Haproxy unchecked return value vulnerability

Haproxy · Haproxy

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.

3.7 CVSS 3.1 Low EPSS 0.55% · top 56.4% CWE-252 · Unchecked return value
3.7CVSS 3.1 base score
0.55%EPSS exploitation probability, 30 days
NoNot in CISA KEV
3Affected product versions listed by NVD
2References
25 Aug 2026Last modified by NVD

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.

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

Affected products

3 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://git.haproxy.org/?p=haproxy-3.2.git;a=commit;h=5bb098ce8a656ec5711b4de3e4c87f12b216e7a1 PatchVendor Advisory
https://www.haproxy.org Product

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2019-19330Haproxy injection vulnerabilityThe HTTP/2 implementation in HAProxy before 2.0.10 mishandles headers, as demonstrated by carriage return (CR, ASCII 0xd), line feed (LF, ASCII 0xa),…EPSS 4.0%9.1CVE-2023-25725Haproxy http request smuggling vulnerabilityHAProxy before 2.7.3 may allow a bypass of access control because HTTP/1 headers are inadvertently lost in some situations, aka "request smuggling." …EPSS 5.4%9.0CVE-2026-55203Haproxy integer overflow vulnerabilityHAProxy through 3.4.0, fixed in commit 5985276, contains an integer overflow vulnerability in the fcgi_conn structure's drl field that allows buffer …EPSS 0.58%8.8CVE-2020-11100HAProxy HPACK decoder heap out-of-bounds writeThe HPACK decoder in HAProxy 1.8 through 2.x before 2.1.4 contains an out-of-bounds write in hpack_dht_insert in hpack-tbl.c. A crafted HTTP/2 reques…EPSS 61%analysed8.7CVE-2026-55204Haproxy null pointer dereference vulnerabilityHAProxy through 3.4.0, fixed in commit 9a6d1fe, contains a null pointer dereference vulnerability in hpack_dht_insert() within src/hpack-tbl.c that f…EPSS 0.48%8.2CVE-2023-45539Haproxy vulnerabilityHAProxy before 2.8.2 accepts # as part of the URI component, which might allow remote attackers to obtain sensitive information or have unspecified o…EPSS 1.5%7.5CVE-2025-11230Haproxy aloha appliance vulnerabilityInefficient algorithm complexity in mjson in HAProxy allows remote attackers to cause a denial of service via specially crafted JSON requests.EPSS 0.69%7.5CVE-2024-45506Haproxy vulnerabilityHAProxy 2.9.x before 2.9.10, 3.0.x before 3.0.4, and 3.1.x through 3.1-dev6 allows a remote denial of service for HTTP/2 zero-copy forwarding (h2_sen…EPSS 1.2%

Source: NIST National Vulnerability Database (record CVE-2026-26080), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.