CVE-2026-61722: Integer Overflow (CVSS 6.8)

Description

FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.5.0 until 2.5.6, the native DLS parser validates articulation chunks using the unsigned expression cbsize + connblocks * 12 without first ensuring that the multiplication and addition fit in 32 bits. A crafted DLS file can supply a large connblocks value that wraps the expression and bypasses the chunk-size check, after which the parser performs approximately one billion 12-byte iterations beyond the chunk boundary. The excessive processing and invalid reads can cause denial of service. Builds with the CMake option enable-native-dls set to OFF do not expose the parser. This issue is fixed in version 2.5.6.

Is your site exposed to CVE-2026-61722?

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

CVSS v3.1 Score

6.8

MEDIUM

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

EPSS — Exploit Prediction

0.0020

Probability of exploitation

0.09%

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-190 Integer Overflow

References

Other References

https://github.com/FluidSynth/fluidsynth/commit/4d7084fca7c876f5d738498b4917a39faf603425 https://github.com/FluidSynth/fluidsynth/releases/tag/v2.5.6 https://github.com/FluidSynth/fluidsynth/security/advisories/GHSA-hp72-35pr-6h6r

Frequently Asked Questions

What is CVE-2026-61722? +

FluidSynth is a software synthesizer based on the SoundFont 2 specifications. From 2.5.0 until 2.5.6, the native DLS parser validates articulation chunks using the unsigned expression cbsize + connblocks * 12 without first ensuring that the multiplication and addition fit in 32 bits. A crafted DLS file can supply a large connblocks value that wraps the expression and bypasses the chunk-size check, after which the parser performs approximately one billion 12-byte iterations beyond the chunk boundary. The excessive processing and invalid reads can cause denial of service. Builds with the CMake option enable-native-dls set to OFF do not expose the parser. This issue is fixed in version 2.5.6. It has a CVSS v3.1 base score of 6.8 (MEDIUM).

How severe is CVE-2026-61722? +

CVE-2026-61722 has a CVSS v3.1 score of 6.8 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0020, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-61722? +

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-2026-53910

diff3 tool from GNU diffutils is vulnerable to a heap‑based buffer overflow due to multiple signed integer overflows in line‑mapping …

CVE-2025-2574

Out-of-bounds array write in Xpdf 4.05 and earlier, due to incorrect integer overflow checking in the PostScript function interpreter code.

CVE-2025-46333

z2d is a pure Zig 2D graphics library. Versions of z2d after `0.5.1` and up to and including `0.6.0`, when …

CVE-2024-30212

If a SCSI READ(10) command is initiated via USB using the largest LBA (0xFFFFFFFF) with it's default block size of …

CVE-2025-52935

Integer Overflow or Wraparound vulnerability in dragonflydb dragonfly (src/redis/lua/struct modules). This vulnerability is associated with program files lua_struct.C. This issue …

CVE-2025-7709

An integer overflow exists in the FTS5 https://sqlite.org/fts5.html extension. It occurs when the size of an array of tombstone pointers …

CVE-2026-61722