CVE-2026-61551 (CVSS 8.6)

Description

Icinga 2 is an open source monitoring system. Prior to 2.14.9, 2.15.4, and 2.16.2, parsing deeply nested JSON can exhaust the call stack because nesting depth is not bounded. The affected JSON parsing paths are reachable by unauthenticated network clients through the Icinga 2 service on TCP port 5665, allowing a remote attacker to crash the process, while possible code execution has not been demonstrated. This issue is fixed in versions 2.14.9, 2.15.4, and 2.16.2.

Is your site exposed to CVE-2026-61551?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

8.6

HIGH

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

EPSS — Exploit Prediction

0.0094

Probability of exploitation

0.60%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-674 CWE-674

References

Other References

Frequently Asked Questions

What is CVE-2026-61551? +

Icinga 2 is an open source monitoring system. Prior to 2.14.9, 2.15.4, and 2.16.2, parsing deeply nested JSON can exhaust the call stack because nesting depth is not bounded. The affected JSON parsing paths are reachable by unauthenticated network clients through the Icinga 2 service on TCP port 5665, allowing a remote attacker to crash the process, while possible code execution has not been demonstrated. This issue is fixed in versions 2.14.9, 2.15.4, and 2.16.2. It has a CVSS v3.1 base score of 8.6 (HIGH).

How severe is CVE-2026-61551? +

CVE-2026-61551 has a CVSS v3.1 score of 8.6 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0094, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-61551? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-8936

Fixed a VM panic caused by unbounded recursion in the grpcfuse kernel module when a container created deeply nested directories …

CVE-2025-10728

When the module renders a Svg file that contains a <pattern> element, it might end up rendering it recursively leading …

CVE-2025-11896

In Xpdf 4.05 (and earlier), a PDF object loop in a CMap, via the "UseCMap" entry, leads to infinite recursion …

CVE-2026-46689

Kanidm is an identity management platform. Prior to version 1.9.3, a single unauthenticated GET to any /scim/v1/... endpoint with a …

CVE-2026-44844

eml_parser serves as a python module for parsing eml files and returning various information found in the e-mail as well …

CVE-2026-89418

google-protobuf contains an unbounded recursion when parsing unknown protobuf group fields. An attacker can send a small crafted payload of …

CVE-2026-61551