Quick answers
- Is CVE-2026-61723 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-61723 being exploited in the wild.
- How severe is CVE-2026-61723?
- 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-2026-61723?
- A patch was published on 2026-07-04: Version 2.5.6 released with fix Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-61723 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-61723?
- 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 native DLS parser fails to check for integer overflow when computing the chunk size using the expression cues * 4 + cbsize, where cues is read from an untrusted DLS file. An attacker can supply a large cues value that wraps the 32-bit arithmetic, bypassing the bounds check and causing subsequent resize operations to request gigabytes of memory and read invalid memory beyond chunk boundaries. The vulnerability exists only when the enable-native-dls option is enabled.
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 with fix