Fedify has an LD-Signature Bypass via JSON-LD Named-Graph Restructuring
Priority LOW 30CWE-1289Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · High · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-347.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00171 6th percentileScored 2026-11-07
Fix Fixed fedify (fedify-dev): 2.2.3, 2.1.14, 2.0.18 +2@fedify/fedify (npm): 2.2.3, 2.1.14, 2.0.18 +2
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| fedify-dev | fedify | 2.2.0 to before 2.2.3; 2.1.0 to before 2.1.14; 2.0.0 to before 2.0.18; 1.10.0 to before 1.10.10; before 1.9.11 | 2.2.3, 2.1.14, 2.0.18, 1.10.10, 1.9.11 | Patch available | CNA |
| — | @fedify/fedify (npm) | 2.2.0 to before 2.2.3 | 2.2.3 | Patch available | GHSA-9rfg-v8g9-9367 |
| — | @fedify/fedify (npm) | 2.1.0 to before 2.1.14 | 2.1.14 | Patch available | GHSA-9rfg-v8g9-9367 |
| — | @fedify/fedify (npm) | 2.0.0 to before 2.0.18 | 2.0.18 | Patch available | GHSA-9rfg-v8g9-9367 |
| — | @fedify/fedify (npm) | 1.10.0 to before 1.10.10 | 1.10.10 | Patch available | GHSA-9rfg-v8g9-9367 |
| — | @fedify/fedify (npm) | before 1.9.11 | 1.9.11 | Patch available | GHSA-9rfg-v8g9-9367 |
- fedify Vendorfedify-dev Affected 2.2.0 to before 2.2.3; 2.1.0 to before 2.1.14; 2.0.0 to before 2.0.18; 1.10.0 to before 1.10.10; before 1.9.11 Fixed in 2.2.3, 2.1.14, 2.0.18, 1.10.10, 1.9.11 Patch available CNA
- @fedify/fedify (npm) Vendor— Affected 2.2.0 to before 2.2.3 Fixed in 2.2.3 Patch available GHSA-9rfg-v8g9-9367
- @fedify/fedify (npm) Vendor— Affected 2.1.0 to before 2.1.14 Fixed in 2.1.14 Patch available GHSA-9rfg-v8g9-9367
- @fedify/fedify (npm) Vendor— Affected 2.0.0 to before 2.0.18 Fixed in 2.0.18 Patch available GHSA-9rfg-v8g9-9367
- @fedify/fedify (npm) Vendor— Affected 1.10.0 to before 1.10.10 Fixed in 1.10.10 Patch available GHSA-9rfg-v8g9-9367
- @fedify/fedify (npm) Vendor— Affected before 1.9.11 Fixed in 1.9.11 Patch available GHSA-9rfg-v8g9-9367
Remediation
- Fix · CNA fedify (fedify-dev) Fixed in 2.2.3, 2.1.14, 2.0.18, 1.10.10, 1.9.11
- Fix · GHSA-9rfg-v8g9-9367 @fedify/fedify (npm) Fixed in 2.2.3 Advisory →
- Fix · GHSA-9rfg-v8g9-9367 @fedify/fedify (npm) Fixed in 2.1.14 Advisory →
- Fix · GHSA-9rfg-v8g9-9367 @fedify/fedify (npm) Fixed in 2.0.18 Advisory →
- Fix · GHSA-9rfg-v8g9-9367 @fedify/fedify (npm) Fixed in 1.10.10 Advisory →
- Fix · GHSA-9rfg-v8g9-9367 @fedify/fedify (npm) Fixed in 1.9.11 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-42462
- 2026-10-03 Alias added: GHSA-9rfg-v8g9-9367
References
More fedify-dev vulnerabilities
- TI-2026-44926 Fedify: Server-Side Request Forgery in getNodeInfo() Allows Access to Internal Network Resources CVSS 4.0HIGH 8.8
- TI-2025-34622 @fedify/fedify: Improper Authentication and Incorrect Authorization CVSS 4.0HIGH 8.7
- TI-2026-36902 Fedify has an incomplete SSRF mitigation after GHSA-p9cg-vqcc-grcx: validatePublicUrl allows special-use IPv4 ranges CVSS 3.1HIGH 8.6
- TI-2025-33806 Hollo renders posts received with form elements and allows submission CVSS 3.1MEDIUM 6.1
Sources
- CVE-2026-42462 · CVE Program
- CVE-2026-42462 · NVD
- FIRST EPSS
- GHSA-9rfg-v8g9-9367 · GitHub Advisory Database · CC BY 4.0
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