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Fencer Intel
high 8.8

CVE-2026-86427 json

LibreNMS before 26.8.0 Argument Injection via graph_title

published 2mo ago modified last mo. also EUVD-2026-72385 , GHSA-3hvv-wxpw-cx83

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository librenms/librenms. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

Summary

LibreNMS before 26.8.0 contains an argument injection vulnerability in the graph_title parameter that allows authenticated attackers to inject arbitrary rrdtool arguments by breaking out of double-quote escaping. Attackers can inject DEF and LINE arguments to read RRD files from unauthorized devices, or use newline injection to execute arbitrary rrdtool commands, bypassing per-device authorization checks.

Patch / fix

  • librenms librenms 26.8.0

Is CVE-2026-86427 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2mo ago

Exploit prediction

0.61% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/librenms/librenms/security/advisories/GHSA-3hvv-wxpw-cx83 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • librenms librenms

Classification

Weakness
  • CWE-77 Improper Neutralization of Special Elements used in a Command

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of librenms/librenms published their own advisory on GitHub. Reviewed sources take precedence over it.