How severe is CVE-2025-59351?

No CVSS score has been assigned to CVE-2025-59351 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-59351?

CVE-2025-59351 affects the following packages: github.com/dragonflyoss/dragonfly (Go), d7y.io/dragonfly/v2 (Go). Ecosystems affected: Go.

How do I fix CVE-2025-59351?

Update github.com/dragonflyoss/dragonfly to 2.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-59351 is resolved across your whole dependency graph.

How do I detect CVE-2025-59351 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/dragonflyoss/dragonfly. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2025-59351 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2025-59351?

O3 pinpoints whether CVE-2025-59351 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2025-59351 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-59351 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What type of vulnerability is CVE-2025-59351?

CVE-2025-59351 is classified as NULL Pointer Dereference (CWE-476). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-59351 published, and has it been updated?

CVE-2025-59351 was published on September 17, 2025 and was last updated on July 31, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

CVE-2025-59351

CVE-2025-59351 is a NULL Pointer Dereference vulnerability in github.com/dragonflyoss/dragonfly. O3 Security confirms whether CVE-2025-59351 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Dragonfly possibly panics due to nil pointer dereference when using variables created alongside an error

Also known asGHSA-4mhv-8rh3-4ghwGO-2025-3970

Published

Sep 17, 2025

Updated

Jul 31, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Jul 31, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

2 pkgs affected

🐹github.com/dragonflyoss/dragonfly🐹d7y.io/dragonfly/v2

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Dragonfly is an open source P2P-based file distribution and image acceleration system. Prior to 2.1.0, the first return value of a function is dereferenced even when the function returns an error. This can result in a nil dereference, and cause code to panic. This vulnerability is fixed in 2.1.0.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/dragonflyoss/dragonfly`	all versions	2.1.0
🐹Go	`d7y.io/dragonfly/v2`	all versions	2.1.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/dragonflyoss/dragonfly. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/dragonflyoss/dragonfly to 2.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-59351 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-59351 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2025-59351. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2025-59351 in your dependencies?

O3 detects CVE-2025-59351 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works