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.
CVE-2026-42462
This high-severity CVE scores 7.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 93% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.0
- EG Score
- 7.0(medium)
- EPSS
- 6.8%
- KEV
- Not listed
Published
May 26, 2026
Last Modified
June 11, 2026
Advisory Details (2)
Auto-updated Jun 11, 2026Linked Data Signature Bypass via JSON-LD Named-Graph Restructuring · Advisory · fedify-dev/fedify · GitHub
https://github.com/fedify-dev/fedify/security/advisories/GHSA-9rfg-v8g9-9367Fedify 2.2.3
Patch available: fedify-dev/fedify 2.2.3
https://github.com/fedify-dev/fedify/releases/tag/2.2.3Vendor Advisories for CVE-2026-42462(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| @fedify/fedify | — | 1.9.11 | — |
Weakness Classification(4)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 32× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 05:52 UTCOSV refresh
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-13 22:30 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-08 15:15 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
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- 2026-06-28 14:07 UTCEPSS rescore
- 2026-06-28 04:56 UTCEPSS rescore
- 2026-06-27 03:08 UTCEPSS rescore
- 2026-06-25 13:49 UTCEPSS rescore
- 2026-06-25 13:49 UTCEPSS rescore
- 2026-06-24 14:05 UTCEPSS rescore
- 2026-06-23 21:33 UTCEPSS rescore
- 2026-06-22 14:25 UTCEPSS rescore
- 2026-06-22 14:25 UTCEPSS rescore
- 2026-06-21 14:56 UTCEPSS rescore
- 2026-06-21 14:56 UTCEPSS rescore
- 2026-06-21 01:59 UTCEPSS rescore
- 2026-06-19 19:25 UTCEPSS rescore
- 2026-06-18 17:52 UTCEPSS rescore
- 2026-06-18 17:52 UTCEPSS rescore
- 2026-06-17 17:53 UTCEPSS rescore
- 2026-06-16 17:52 UTCEPSS rescore
- 2026-06-15 17:49 UTCEPSS rescore
- 2026-06-13 23:00 UTCEPSS rescore
- 2026-06-12 23:12 UTCEPSS rescore
- 2026-06-12 23:12 UTCEPSS rescore
- 2026-06-11 14:00 UTCEPSS rescore
- 2026-05-27 00:14 UTCEG score recompute
Frequently asked(5)
What is CVE-2026-42462?
When was CVE-2026-42462 disclosed?
Is CVE-2026-42462 actively exploited?
What is the CVSS score of CVE-2026-42462?
How do I remediate CVE-2026-42462?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-42462
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