go-f3 is Vulnerable to Cached Justification Verification Bypass

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

go-f3 is a Golang implementation of Fast Finality for Filecoin (F3). In versions 0.8.8 and below, go-f3's justification verification caching mechanism has a vulnerability where verification results are cached without properly considering the context of the message. An attacker can bypass justification verification by submitting a valid message with a correct justification and then reusing the same cached justification in contexts where it would normally be invalid. This occurs because the cached verification does not properly validate the relationship between the justification and the specific message context it's being used with. This issue is fixed in version 0.8.9.

Source published

29 Sep 2025 22:38:42 UTC

Source modified

30 Sep 2025 14:13:56 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 5.9 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L

go-f3 is a Golang implementation of Fast Finality for Filecoin (F3). In versions 0.8.8 and below, go-f3's justification verification caching mechanism has a vulnerability where verification results are cached without properly considering the context of the message. An attacker can bypass justification verification by submitting a valid message with a correct justification and then reusing the same cached justification in contexts where it would normally be invalid. This occurs because the cached verification does not properly validate the relationship between the justification and the specific message context it's being used with. This issue is fixed in version 0.8.9.

Source published

Sep 29, 2025, 10:38:42 PM (timezone not stated)

Source modified

Sep 30, 2025, 2:13:56 PM (timezone not stated)

Observed here

9 Nov 2026 03:16:06 UTC

Source terms

ENISA EUVD · source terms and attribution apply

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 5.9 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L

go-f3 is a Golang implementation of Fast Finality for Filecoin (F3). In versions 0.8.8 and below, go-f3's justification verification caching mechanism has a vulnerability where verification results are cached without properly considering the context of the message. An attacker can bypass justification verification by submitting a valid message with a correct justification and then reusing the same cached justification in contexts where it would normally be invalid. This occurs because the cached verification does not properly validate the relationship between the justification and the specific message context it's being used with. This issue is fixed in version 0.8.9.

Source published

29 Sep 2025 23:15:32 UTC

Source modified

9 Oct 2026 09:10:00 UTC

Observed here

25 Oct 2026 03:17:27 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 5.9 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L

CVSS 3.1 · [email protected] · Primary · 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L

### Description A vulnerability exists in go-f3's justification verification caching mechanism where verification results are cached without properly considering the context of the message. An attacker can bypass justification verification by: 1. First submitting a valid message with a correct justification 2. Then reusing the same cached justification in contexts where it would normally be invalid This occurs because the cached verification does not properly validate the relationship between the justification and the specific message context it's being used with. ### Impact - Potential consensus integrity issues through invalid justification acceptance - Could affect network liveness if exploited systematically - May allow malicious actors to influence consensus decisions with invalid justifications - Requires significant power (350+ TiB due to power table rounding) to meaningfully exploit - It would also be difficult to exploit in a synchronised fashion, such that >1/3 of the network goes down at one time. This isn't a one-msg panic, where you can spam it and bring everyone down, because every node will have a different amount of memory andmany SPs also run redundant lotus nodes. ### Patches The fix was merged and released with go-f3 0.8.9. All node software (Lotus, Forest, Venus) are using a patched version of go-f3 with their updates for the nv27 network upgrade. ### 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 bug was reported by @lgprbs via our bug bounty program. Thank you for the contributions.

Source published

29 Sep 2025 20:40:02 UTC

Source modified

23 Oct 2025 20:32:35 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L

Publisher rating · MODERATE

go-f3 Vulnerable to Cached Justification Verification Bypass in github.com/filecoin-project/go-f3

Source published

23 Oct 2025 16:25:09 UTC

Source modified

3 Mar 2026 04:56:57 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.