CVE-2026-58264Network attack vectorHinoki check available

Remote code execution via unchecked channel index

Published Sep 18, 2026 · Updated Sep 18, 2026

Heap-based buffer overflow in FluidSynth 1.1.2 through 2.5.5 allows remote attackers to execute code via its TCP command server. The fluid_handle_pitch_bend_range handler converts the channel argument and indexes handler->synth->channel without checking its bounds before writing the supplied range value. Remote reachability requires the TCP server enabled through new_fluid_server() or fluidsynth -s; local shell input can instead cause a crash or code execution.

CVSS severity9.8
Critical
EPSS probability0.59%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Heap-based buffer overflow in FluidSynth 1.1.2 through 2.5.5 allows remote attackers to execute code via its TCP command server. The fluid_handle_pitch_bend_range handler converts the channel argument and indexes handler->synth->channel without checking its bounds before writing the supplied range value. Remote reachability requires the TCP server enabled through new_fluid_server() or fluidsynth -s; local shell input can instead cause a crash or code execution.

The record

CVE
CVE-2026-58264
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
FluidSynth
Product
FluidSynth
Classifications
CWE-122, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 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=>= 1.1.2, < 2.5.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FluidSynth · FluidSynthversion=>= 1.1.2, < 2.5.6

Published CVSS scores

9.8GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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