What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-10 · updated 2026-07-23
• Weakness: CWE-180

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 products

• fedify-dev fedify: from 2.2.0, < 2.2.3; from 2.1.0, < 2.1.14; from 2.0.0, < 2.0.18; from 1.10.0, < 1.10.10; before 1.9.11

References

• https://github.com/fedify-dev/fedify/releases/tag/2.2.3
• https://github.com/fedify-dev/fedify/security/advisories/GHSA-9rfg-v8g9-9367

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