CVE-2025-59348

Dragonfly incorrectly handles a task structure’s usedTrac field

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at [email protected].

The processPieceFromSource method (figure 4.1) is part of a task processing mechanism. The method writes pieces of data to storage, updating a Task structure along the way. The method does not update the structure’s usedTraffic field, because an uninitialized variable n is used as a guard to the AddTraffic method call, instead of the result.Size variable.

var n int64
result.Size, err = pt.GetStorage().WritePiece([skipped])
result.FinishTime = time.Now().UnixNano()
if n > 0 {
       pt.AddTraffic(uint64(n))
}

A task is processed by a peer. The usedTraffic metadata is not updated during the processing. Rate limiting is incorrectly applied, leading to a denial-of-service condition for the peer.

Kodem intelligence

Already deployed Kodem?

• Dragonfy v2.1.0 and above.

1. What is CVE-2025-59348? CVE-2025-59348 is a medium-severity security vulnerability in github.com/dragonflyoss/dragonfly (go), affecting versions < 2.1.0. It is fixed in 2.1.0.
2. Which packages are affected by CVE-2025-59348?
   • github.com/dragonflyoss/dragonfly (go) (versions < 2.1.0)
   • d7y.io/dragonfly/v2 (go) (versions < 2.1.0)
3. Is there a fix for CVE-2025-59348? Yes. CVE-2025-59348 is fixed in 2.1.0. Upgrade to this version or later.
4. Is CVE-2025-59348 exploitable, and should I be worried? Whether CVE-2025-59348 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether CVE-2025-59348 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix CVE-2025-59348?
   • Upgrade github.com/dragonflyoss/dragonfly to 2.1.0 or later
   • Upgrade d7y.io/dragonfly/v2 to 2.1.0 or later

Other vulnerabilities in github.com/dragonflyoss/dragonfly