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

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.

Published: 2026-04-07 Last update: 2026-04-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-35480 is rated Low Risk (25.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-35480

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-08 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-35480

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.2 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.5 3.6 [email protected]

Weakness enumeration for CVE-2026-35480

GitHub Security Advisory for CVE-2026-35480

GHSA-378j-3jfj-8r9f · Severity: medium · Ecosystem: go — go-ipld-prime: DAG-CBOR decoder unbounded memory allocation from CBOR headers

OS Trackers for CVE-2026-35480

vendor priority summary link
suse medium CVE-2026-35480 severity moderate: SUSE including 1 source package names (kubo-0.40.1-1.1), 1 product×package rows across 1 product lines (openSUSE Tumbleweed): Fixed 1. https://www.suse.com/security/cve/CVE-2026-35480/

Affected software / configurations for CVE-2026-35480

Vendor Product Version Raw CPE
protocol go-ipld-prime < 0.22.0 cpe:2.3:a:protocol:go-ipld-prime:*:*:*:*:*:go:*:*

References for CVE-2026-35480

cvelogic Threat Intelligence