Quick answers
- Is CVE-2026-61722 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-61722 being exploited in the wild.
- How severe is CVE-2026-61722?
- Medium severity, with a CVSS score of 6.8, published 18 September 2026.
- Which products and versions are affected?
- FluidSynth 2.5.0 to 2.5.5.
- Is there a fix for CVE-2026-61722?
- A patch was published on 2026-07-04: version 2.5.6 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-61722 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-61722?
- Check whether you run FluidSynth at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The DLS parser performs an unsigned integer arithmetic operation (cbsize + connblocks * 12) without validating for 32-bit overflow, allowing a large connblocks value to wrap the result and bypass chunk-size validation. An attacker can trigger approximately one billion invalid 12-byte memory iterations past the chunk boundary, causing excessive CPU usage and invalid memory access. The vulnerability is fixed in version 2.5.6 and does not affect builds compiled with enable-native-dls disabled.
Affected products
- FluidSynth FluidSynth 2.5.0 to 2.5.5
Timeline
- 2026-09-18: disclosed
- 2026-07-04: patched: version 2.5.6 released