# CVE-2026-35480: go-ipld-prime's DAG-CBOR decoder unbounded memory allocation from CBOR headers

> An attacker can cause excessive memory allocation and denial of service by sending crafted CBOR payloads to the go-ipld-prime decoder.

- **Severity:** Medium 6.2 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Apr 2026
- **Updated:** 9 Apr 2026
- **Also known as:** GHSA-378j-3jfj-8r9f, GO-2026-5073, MINI-hf9w-8rw7-4rvf, MINI-wqwj-cpw9-4q92

## What is CVE-2026-35480?

CVE-2026-35480 is a medium-severity denial of service vulnerability in go-ipld-prime, published on 7 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-35480?

3 open source packages ship an affected version, including github.com/ipld/go-ipld-prime. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/ipld/go-ipld-prime` | Go | All versions | 0.22.0 |
| `github.com/ipld/go-ipld-prime` | Go | All versions | 0.22.0 |
| `github.com/ipld/go-ipld-prime` | Go | All versions | 0.22.0 |

Products: Protocol Go-Ipld-Prime.

## How do I fix CVE-2026-35480?

Upgrade github.com/ipld/go-ipld-prime to 0.22.0 or later.

## Is CVE-2026-35480 being exploited?

There is no known exploitation of CVE-2026-35480 in the wild and no public exploit code.

## Other vulnerabilities in go-ipld-prime

- [CVE-2023-22460](https://insights.sbomify.com/CVE-2023-22460/): go-ipld-prime json codec may panic if asked to encode bytes (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-35480 and fix it if it is affected.

What it is: CVE-2026-35480 is a medium-severity denial of service vulnerability in go-ipld-prime, published on 7 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-35480 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/ipld/go-ipld-prime (Go): affected all versions; fixed in 0.22.0
- github.com/ipld/go-ipld-prime (Go): affected all versions; fixed in 0.22.0
- github.com/ipld/go-ipld-prime (Go): affected all versions; fixed in 0.22.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-35480/ (Markdown: https://insights.sbomify.com/CVE-2026-35480/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-35480
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35480
- OSV: https://osv.dev/vulnerability/CVE-2026-35480

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-35480/
Summaries are generated and may contain mistakes; the official description above is the record.