CVE-2026-48549Network attack vectorHinoki check available

Command execution via double-submit cookie bypass

Published Aug 26, 2026 · Updated Aug 28, 2026

CSRF in cmd.cgi in Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 allows remote attackers to execute Nagios commands. Without a Cookie header, cmd.cgi treated matching attacker-supplied NagFormId and nagFormId POST values as a valid double-submit token. Exploitation requires an authenticated user to initiate the cross-site request, and resulting actions are bounded by that user's Nagios command authorization.

CVSS severity6.9
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

CSRF in cmd.cgi in Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 allows remote attackers to execute Nagios commands. Without a Cookie header, cmd.cgi treated matching attacker-supplied NagFormId and nagFormId POST values as a valid double-submit token. Exploitation requires an authenticated user to initiate the cross-site request, and resulting actions are bounded by that user's Nagios command authorization.

The record

CVE
CVE-2026-48549
Published
Aug 26, 2026
Updated
Aug 28, 2026
Vendor
Nagios Enterprises, LLC
Product
Nagios Core
Classifications
CWE-352, T1204
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <4.5.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Nagios Enterprises, LLC · Nagios Coreversion=0 <4.5.13
Nagios Enterprises, LLC · Nagios XIversion=0 <2026R1.5

Published CVSS scores

6.9VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
6.5VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)
T1204User Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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