Vulnerability · Published Jun 10, 2026 · Assigned by GitHub_M

CVE-2026-42462Fedify has an LD-Signature Bypass via JSON-LD Named-Graph Restructuring

High 7.0

In plain English

A high-severity security flaw in fedify from fedify-dev. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.0High
Exploit odds (30 days)0.2%top 93.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Prior to versions 1.9.11, 1.10.10, 2.0.18, 2.1.14, and 2.2.3, an attacker can make use of JSON-LD features to restructure a JSON-LD document that would change how Fedify interprets it without changing its Linked Data Signature, allowing them to alter a third-party signed activity they have received. Versions 1.9.11, 1.10.10, 2.0.18, 2.1.14, and 2.2.3 fix the issue.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
npm@fedify/fedify2.2.3GHSA-9rfg-v8g9-9367
npm@fedify/fedify2.1.14GHSA-9rfg-v8g9-9367
npm@fedify/fedify2.0.18GHSA-9rfg-v8g9-9367
npm@fedify/fedify1.10.10GHSA-9rfg-v8g9-9367
npm@fedify/fedify1.9.11GHSA-9rfg-v8g9-9367

Affected products (as reported)

VendorProductVersions
fedify-dev fedify >= 2.2.0, < 2.2.3>= 2.1.0, < 2.1.14>= 2.0.0, < 2.0.18>= 1.10.0, < 1.10.10< 1.9.11

Weakness: CWE-180, CWE-347, CWE-436, CWE-1289 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L

References