# CVE-2025-59348: Dragonfly incorrectly handles a task structure’s usedTraffic field

> Attackers can cause denial of service in Dragonfly peers by exploiting incorrect traffic accounting that bypasses rate limiting.

- **Severity:** Medium 5.5 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2025
- **Updated:** 17 Sep 2025
- **Also known as:** GHSA-2qgr-gfvj-qpcr, GO-2025-3963

## What is CVE-2025-59348?

CVE-2025-59348 is a medium-severity denial of service vulnerability in dragonflyoss dragonfly, published on 17 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Dragonfly is an open source P2P-based file distribution and image acceleration system. Prior to 2.1.0, the processPieceFromSource 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. 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. This vulnerability is fixed in 2.1.0.

Weakness: CWE-457 (Use of Uninitialized Variable)

## Which versions are affected by CVE-2025-59348?

6 open source packages ship an affected version, including github.com/dragonflyoss/dragonfly and d7y.io/dragonfly/v2. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/dragonflyoss/dragonfly` | Go | All versions | None |
| `github.com/dragonflyoss/dragonfly` | Go | All versions | 2.1.0 |
| `github.com/dragonflyoss/dragonfly` | Go | All versions | 2.1.0 |
| `d7y.io/dragonfly/v2` | Go | All versions | 2.1.0 |
| `d7y.io/dragonfly/v2` | Go | All versions | 2.1.0 |
| `d7y.io/dragonfly/v2` | Go | All versions | 2.1.0 |

Products: Linuxfoundation Dragonfly.

## How do I fix CVE-2025-59348?

Upgrade github.com/dragonflyoss/dragonfly to 2.1.0 or later.

## Is CVE-2025-59348 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-59348 exists.

## Other vulnerabilities in dragonflyoss dragonfly

- [CVE-2023-27584](https://insights.sbomify.com/CVE-2023-27584/): Dragonfly2 vulnerable to hard coded cyptographic key (critical 9.8)
- [CVE-2026-24124](https://insights.sbomify.com/CVE-2026-24124/): Dragonfly Manager Job API Allows Unauthenticated Access (high 8.9)
- [CVE-2025-59345](https://insights.sbomify.com/CVE-2025-59345/): Dragonfly did not enable authentication for some Manager’s endpoints (high 7.7)
- [CVE-2025-59353](https://insights.sbomify.com/CVE-2025-59353/): Manager generates mTLS certificates for arbitrary IP addresses (high 7.7)
- [CVE-2025-59352](https://insights.sbomify.com/CVE-2025-59352/): Dragonfly allows arbitrary file read and write on a peer machine (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-59348 and fix it if it is affected.

What it is: CVE-2025-59348 is a medium-severity denial of service vulnerability in dragonflyoss dragonfly, published on 17 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-59348 exists.

Affected packages and fixed versions:
- github.com/dragonflyoss/dragonfly (Go): affected all versions; no fix listed
- github.com/dragonflyoss/dragonfly (Go): affected all versions; fixed in 2.1.0
- github.com/dragonflyoss/dragonfly (Go): affected all versions; fixed in 2.1.0
- d7y.io/dragonfly/v2 (Go): affected all versions; fixed in 2.1.0
- d7y.io/dragonfly/v2 (Go): affected all versions; fixed in 2.1.0
- d7y.io/dragonfly/v2 (Go): affected all versions; fixed in 2.1.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-59348/ (Markdown: https://insights.sbomify.com/CVE-2025-59348/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-59348
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-59348
- OSV: https://osv.dev/vulnerability/CVE-2025-59348

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-59348/
Summaries are generated and may contain mistakes; the official description above is the record.