6.9
MEDIUM CVSS 4.0
CVE-2026-111123
FluidSynth through 2.6.1 Out-of-Bounds Write via SoundFont Modulator Destination
Description

FluidSynth through 2.6.1 contains an out-of-bounds write vulnerability that allows attackers to corrupt heap and stack memory by supplying unvalidated SoundFont modulator destination values. Attackers can craft an SF2 file with PMOD/IMOD destinations of 63 to 255 that, when loaded and played, write past the voice generator array and updated_gen_bit, causing memory corruption and crashes.

INFO

Published Date :

Oct. 15, 2026, 7:17 p.m.

Last Modified :

Oct. 15, 2026, 8:17 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-111123 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Fluidsynth fluidsynth
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM MITRE-CVE
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Update FluidSynth to fix heap and stack memory corruption via SoundFont modulator values.
  • Update FluidSynth to a version later than 2.6.1.
  • Avoid loading untrusted SoundFont files.
  • Validate SoundFont modulator destination values.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-111123 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-111123 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-111123 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-111123 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 15, 2026

    Action Type Old Value New Value
    Added Reference https://hackmd.io/@haind-pwn/fluidsynth-sf2-modulator-dest-generator-oob-write
    Added SSVC {'id': 'CVE-2026-111123', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-15T19:46:04.553463Z'}
  • New CVE Received by [email protected]

    Oct. 15, 2026

    Action Type Old Value New Value
    Added Description FluidSynth through 2.6.1 contains an out-of-bounds write vulnerability that allows attackers to corrupt heap and stack memory by supplying unvalidated SoundFont modulator destination values. Attackers can craft an SF2 file with PMOD/IMOD destinations of 63 to 255 that, when loaded and played, write past the voice generator array and updated_gen_bit, causing memory corruption and crashes.
    Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/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
    Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
    Added CWE CWE-787
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/111xxx/CVE-2026-111123.json">CVE-2026-111123</a>
    Added Reference https://github.com/FluidSynth/fluidsynth
    Added Reference https://github.com/FluidSynth/fluidsynth/blob/71e85b2ca6bf48641ba7e2261d8f2640ae473773/src/sfloader/fluid_defsfont.c#L1609-L1611
    Added Reference https://github.com/FluidSynth/fluidsynth/blob/71e85b2ca6bf48641ba7e2261d8f2640ae473773/src/synth/fluid_voice.c#L1184-L1229
    Added Reference https://github.com/FluidSynth/fluidsynth/blob/71e85b2ca6bf48641ba7e2261d8f2640ae473773/src/synth/fluid_voice.c#L615-L623
    Added Reference https://hackmd.io/@haind-pwn/fluidsynth-sf2-modulator-dest-generator-oob-write
    Added Reference https://www.vulncheck.com/advisories/fluidsynth-through-2.6.1-out-of-bounds-write-via-soundfont-modulator-destination
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.