CVE-2026-42462

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

HIGH

CVSS Score

Published: June 10, 2026 at 08:22 PM UTC

Updated: July 23, 2026 at 07:32 PM UTC

1 product affected across 1 vendorFedify

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Severity

HIGH7

Exploit prediction

EPSS 0.2%

SSVC

No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Fedify · Fedify Dev

60%

v < 1.10.10v < 1.9.11v < 2.0.18v < 2.1.14v < 2.2.3

Affected range stops below 1.10.10, so it looks safe — our inference, not a vendor statement

Affected range stops below 1.9.11, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.0.18, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.1.14, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.2.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (2)

x_refsource_CONFIRM

Source: cverecord

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

x_refsource_MISC

Source: cverecord

https://github.com/fedify-dev/fedify/releases/tag/2.2.3

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7HIGHGitHub_M

Attack Vector: NETWORK
Complexity: HIGH
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: LOW
Integrity: HIGH
Availability: LOW

Vector?

Quick Info

StatusDEFERRED

CWE

CWE-180CWE-347CWE-436CWE-1289

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