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HIGH severity

go-merkledag's ProtoNode may be modified such that common method calls may panicGHSA-x39j-h85h-3f46

HIGHFix: ipfs/go-merkledag#91

GHSA-x39j-h85h-3f46 is a high-severity (CVSS 7.5) CWE-755 vulnerability in github.com/ipfs/go-merkledag. A fix is available for github.com/ipfs/go-merkledag — see the affected versions and patch details below.

Also known asCVE-2022-23495GO-2022-1155
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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 GHSA-x39j-h85h-3f46.

EPSS Exploitation Probability

via FIRST.org ↗
1.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs72th percentile — riskier than 72% of all scored CVEsHighest risk
0.75%1.51%2.26%3.01%2.5%1.3%1.3%1.4%1.4%Jun 26Oct 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
🐹github.com/ipfs/go-merkledag

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

Impact

A ProtoNode may be modified in such a way as to cause various encode errors which will trigger a panic on common method calls that don't allow for error returns.

A ProtoNode should only be able to encode to valid DAG-PB, attempting to encode invalid DAG-PB forms will result in an error from the codec. Manipulation of an existing (newly created or decoded) ProtoNode using the modifier methods did not account for certain states that would place the ProtoNode into an unencodeable form.

Due to conformance with the github.com/ipfs/go-block-format#Block and github.com/ipfs/go-ipld-format#Node interfaces, certain methods, which internally require a re-encode if state has changed, will panic due to the inability to return an error.

Additionally, use of the ProtoNode#SetCidBuilder() method to set a non-functioning CidBuilder (such as one that refers to a multihash where an implementation of that hash function is not available) may cause the same methods to panic as a new CID is required but cannot be created.

Patches

Releases involving fixes for this issue are v0.8.0 and v0.8.1. The recommended minimum version is v0.8.1.

  • Additional checks are performed on ProtoNode state changes to avoid the possibility of creating unencodeable forms, errors are returned where this is the case.
  • The builder passed in to SetCidBuilder() is inspected to attempt to determine if it is usable to generate CIDs, otherwise an error is returned.
  • The panics have been removed and replaced with default values (empty byte slice for RawData() and a default zero-bytes DAG-PB CID for methods involving CIDs).

Workarounds

These workarounds are available when using impacted versions to avoid panic conditions, and may be generally appropriate in order to provide meaningful feedback to users and avoid generating bad, or unexpected encoded data:

  • Sanitise inputs when allowing user-input to set a new CidBuilder on a ProtoNode.
  • Sanitise Tsize (Link#Size) values such that they are a reasonable byte-size for sub-DAGs where derived from user-input.

References

Credit

Thanks to @mrd0ll4r for reporting the original error to Kubo!

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/ipfs/go-merkledag≥ 0.4.0&&< 0.8.10.8.1go get github.com/ipfs/go-merkledag@v0.8.1

Affected Products

1 product · 1 configurations
Application
go-merkledagprotocol
≥ 0.4.0 && < 0.8.1
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ipfs/go-merkledag, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update github.com/ipfs/go-merkledag to 0.8.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x39j-h85h-3f46 is resolved across your whole dependency graph.

  3. 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.

Frequently Asked Questions

### Impact A `ProtoNode` may be modified in such a way as to cause various encode errors which will trigger a panic on common method calls that don't allow for error returns. A `ProtoNode` should only be able to encode to valid DAG-PB, attempting to encode invalid DAG-PB forms will result in an error from the codec. Manipulation of an existing (newly created or decoded) `ProtoNode` using the modifier methods did not account for certain states that would place the `ProtoNode` into an unencodeable form. Due to conformance with the [`github.com/ipfs/go-block-format#Block`](https://pkg.go.dev/g
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