CVE-2025-59942 — go-f3
HIGHCVE-2025-59942 is a high-severity (CVSS 7.5) CWE-190 vulnerability in github.com/filecoin-project/go-f3. A fix is available for github.com/filecoin-project/go-f3 — see the affected versions and patch details below.
go-f3 module vulnerable to integer overflow leading to panic
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-59942.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2025-59942 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/filecoin-project/go-f3Real-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
Impact
Filecoin nodes consuming F3 messages are vulnerable. go-f3 panics when it validates a "poison" messages. A "poison" message can can cause integer overflow in the signer index validation. In Lotus' case, the whole node will crash.
There is no barrier to entry. An attacker doesn't need any power to pull off this attack.
These malicious messages aren't self-propagating since the bug is in the validator. An attacker needs to directly send the message to all targets.
Patches
The fix was merged and released with go-f3 0.8.7. All node software (Lotus, Forest, Venus) are using a patched version of go-f3 with their updates for the nv27 network upgrade.
go-f3 now does proper overflow checking using math.MaxInt64 comparison and returns error "justificationPower overflow" when overflow would occur.
Workarounds
The are no immediate workarounds available. Nodes should upgrade to the patched version, which they will have done if participating in nv27 on Filecoin mainnet.
Credits
The initial finding(unrelated path) was reported by 0xNirix via bug bounty program which wasn't high issue. The further digging by developers led to this finding. Thank you for the contributions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/filecoin-project/go-f3 | all versions | 0.8.7go get github.com/filecoin-project/go-f3@v0.8.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/filecoin-project/go-f3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/filecoin-project/go-f3 to 0.8.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-59942 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-59942 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-59942. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-59942 in your dependencies?
O3 Security finds CVE-2025-59942 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.