# CVE-2026-35480: GO-2026-5073 - DAG-CBOR decoder unbounded memory allocation from CBOR headers in github.com/ipld/go-ipld-prime

Source: https://junglewise.ai/threats/cve-2026-35480-go-ipld-prime-dag-cbor-decoder-unbounded-memory-allocation-from  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-07  
License: CC BY 4.0 with a link back

CVE-2026-35480 · Severity: medium · CVSS 6.2 · Published 2026-04-07

go-ipld-prime is an implementation of the InterPlanetary Linked Data (IPLD) spec interfaces, a batteries-included codec implementations of IPLD for CBOR and JSON, and tooling for basic operations on IPLD objects. Prior to 0.22.0, the DAG-CBOR decoder uses collection sizes declared in CBOR headers as Go preallocation hints for maps and lists. The decoder does not cap these size hints or account for their cost in its allocation budget, allowing small payloads to cause excessive memory allocation. This vulnerability is fixed in 0.22.0.

Technologies: [github.com/ipld/go-ipld-prime (Go)](https://junglewise.ai/threats/technologies/github-com-ipld-go-ipld-prime). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-35480 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-35480 being exploited in the wild.

**How severe is CVE-2026-35480?** Medium severity, with a CVSS score of 6.2, published 7 April 2026.

**Which products and versions are affected?** github.com/ipld/go-ipld-prime (Go) SEMVER:introduced=0,fixed=0.22.0.

**Is there a fix for CVE-2026-35480?** Yes. github.com/ipld/go-ipld-prime (Go): upgrade to 0.22.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-35480?** Check whether you run github.com/ipld/go-ipld-prime (Go) or Protocol Go-Ipld-Prime at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/ipld/go-ipld-prime (Go): upgrade to 0.22.0 or later

  ```sh
  go get github.com/ipld/go-ipld-prime@v0.22.0
  ```


## Affected products

- github.com/ipld/go-ipld-prime (Go) SEMVER:introduced=0,fixed=0.22.0
- Protocol Go-Ipld-Prime

## Identifiers

- CVE-2026-35480
- GHSA-378j-3jfj-8r9f
- GO-2026-5073

## Related threats

- [IPLD go-ipld-prime uncontrolled recursion in DAG-CBOR and DAG-JSON decoders](https://junglewise.ai/threats/cve-2026-42328-ipld-go-ipld-prime-uncontrolled-recursion-in-dag-cbor-and-dag)
- [GO-2023-1269 - Panic in encoding in github.com/ipld/go-ipld-prime](https://junglewise.ai/threats/cve-2023-22460-go-ipld-prime-codec-json-may-panic-if-asked-to-encode-bytes)