CVE-2026-26080: Unchecked Return Value in Haproxy Aloha

0

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

No scoring signals.

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

—

No EPSS score.

Affects

Haproxy

Aloha and 2 more

CVSS base

3.7

Low · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

No

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — git.haproxy.org (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Haproxy Aloha, Haproxy Haproxy, Haproxy Haproxy Enterprise).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes matching the vulnerability class (logic error), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Haproxy	Aloha	≥ 17.5.0 and < 17.5.16≥ 17.0.0 and < 17.0.18	Vulnerable	NIST National Vulnerability Database
Haproxy	Haproxy	≥ 3.3 and < 3.3.3≥ 3.2 and < 3.2.12	Vulnerable	NIST National Vulnerability Database
Haproxy	Haproxy	≥ 3.2 and < 3.2.12≥ 3.3 and < 3.3.3	Vulnerable	CVE Program (cve.org) e CISA ADP
Haproxy	Haproxy Enterprise	version 3.2r1-1.0.0-359.440version 3.2r1-1.0.0-365.545version 3.2r1-1.0.0-365.531version 3.2r1-1.0.0-365.529version 3.2r1-1.0.0-363.511version 3.2r1-1.0.0-363.498version 3.2r1-1.0.0-363.478version 3.2r1-1.0.0-363.476 and 12 more version 3.2r1-1.0.0-362.473version 3.2r1-1.0.0-360.460version 3.2r1-1.0.0-358.439version 3.2r1-1.0.0-354.439version 3.2r1-1.0.0-354.402version 3.2r1-1.0.0-353.398version 3.2r1-1.0.0-353.385version 3.2r1-1.0.0-353.376version 3.2r1-1.0.0-353.355version 3.2r1-1.0.0-353.347version 3.2r1-1.0.0-353.336version 3.2r1-1.0.0-353.334	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

High

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
3.7	CVSS 3.1	Low	2.2	1.4	cve@mitre.org via NIST National Vulnerability Database
3.7	CVSS 3.1	Low	—	—	mitre via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L (score shown at the top: cve@mitre.org)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-252 · Unchecked Return Value

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · haproxy/haproxy
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
Fix documented
Oct 15, 2026 · NIST National Vulnerability Database
CVSS changed · 3.7
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Jul 20, 2026 · mitre

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

2 on the record

git.haproxy.org/
Patch, Vendor Advisory, NIST National Vulnerability Database
www.haproxy.org
Product, NIST National Vulnerability Database

Elsewhere on this site

Haproxy
every CVE for this vendor

Logic error
same class

CWE-252
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-90678 An issue was discovered in HAProxy 3.3.0 through 3.4.4 and in 3.5-dev1 through 3.5-dev5… Sep 13, 2026
Medium CVE-2026-26081 HAProxy Community Edition 3.0 through 3.3 before 3.3.3 lacks a length check for the… Jul 20, 2026
Critical CVE-2026-55203 HAProxy - Integer Overflow in FCGI Demux Record Length Field Jun 18, 2026
High CVE-2026-55204 HAProxy - NULL Pointer Dereference in hpack_dht_insert Function Jun 18, 2026
Medium CVE-2026-33555 An issue was discovered in HAProxy before 3.3.6. The HTTP/3 parser does not check that… Apr 13, 2026
High CVE-2025-11230 Denial of service vulnerability in HAProxy mjson library Nov 19, 2025

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No FIRST EPSS score.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-26080 is "Unchecked Return Value in Haproxy Aloha", rated Low. It affects Aloha (Haproxy); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 3.7 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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