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NVD / CVE Program· CNA GitHub_M

CVE-2026-50131: Fedify has an incomplete SSRF mitigation after GHSA-p9cg-vqcc-grcx: validatePublicUrl allows special-use IPv4 ranges

Noroxi assessment

Priority: Monitor (action score 34/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.35% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: @fedify/fedify (npm) 1.9.12, 1.10.11, 2.0.19; @fedify/vocab-runtime (npm) 2.1.15, 2.2.4, 2.0.19.

Low priority for now. Upgrade to @fedify/fedify (npm) 1.9.12, 1.10.11, 2.0.19; @fedify/vocab-runtime (npm) 2.1.15, 2.2.4, 2.0.19 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Fedify is a TypeScript library for building federated server apps powered by ActivityPub. Fedify previously addressed SSRF/internal network access in GHSA-p9cg-vqcc-grcx by adding public URL validation before runtime document and media fetching. However, the IPv4 validation logic present starting in version 0.11.2 and prior to versions 1.9.12, 1.10.11, 2.0.19, 2.1.15, and 2.2.4 appears incomplete. The `validatePublicUrl()` protection relies on `isValidPublicIPv4Address()` to reject non-public IPv4 destinations. The function blocks common private and local ranges such as `10.0.0.0/8`, `127.0.0.0/8`, `169.254.0.0/16`, `172.16.0.0/12`, and `192.168.0.0/16`, but it still treats several special-use, reserved, multicast, benchmarking, and carrier-grade NAT IPv4 ranges as valid public destinations. Because this validation is used as an SSRF defense before outbound fetches, this appears to be an incomplete mitigation or bypass class for the previous SSRF issue. Versions 1.9.12, 1.10.11, 2.0.19, 2.1.15, and 2.2.4 contain an updated patch.

HighCVSS 8.6 · v3.1—Proof of concept Fix available
Published
Jun 10, 2026
Updated
Jul 21, 2026
EPSS
0.3% · 28th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.6 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.6
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • fedify-dev fedify

    • >= 0.11.2, < 1.9.12, >= 1.10.0, < 1.10.11, >= 2.0.0, < 2.0.19, >= 2.1.0, < 2.1.15, >= 2.2.0, < 2.2.4affected

  • fedify-dev vocab-runtime

    • < 2.0.19, >= 2.1.0, < 2.1.15, >= 2.2.0, < 2.2.4affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
npm@fedify/fedifyfrom 0.11.2 · before 1.9.121.9.12
npm@fedify/fedifyfrom 1.10.0 · before 1.10.111.10.11
npm@fedify/fedifyfrom 2.0.0 · before 2.0.192.0.19
npm@fedify/fedifyfrom 2.1.0 · before 2.1.152.1.15
npm@fedify/fedifyfrom 2.2.0 · before 2.2.42.2.4
npm@fedify/vocab-runtimefrom 2.1.0 · before 2.1.152.1.15
npm@fedify/vocab-runtimefrom 2.2.0 · before 2.2.42.2.4
npm@fedify/vocab-runtimebefore 2.0.192.0.19

Same product

fedify-dev: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-62857Fedify: Server-Side Request Forgery in getNodeInfo() Allows Access to Internal Network Resources
    35Monitor
  • CVE-2025-54888@fedify/fedify: Improper Authentication and Incorrect Authorization
    34Monitor
  • CVE-2026-42462Fedify has an LD-Signature Bypass via JSON-LD Named-Graph Restructuring
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
npm:@fedify/fedify1.10.11Package registry (OSV)
npm:@fedify/fedify1.9.12Package registry (OSV)
npm:@fedify/fedify2.0.19Package registry (OSV)
npm:@fedify/fedify2.1.15Package registry (OSV)
npm:@fedify/fedify2.2.4Package registry (OSV)
npm:@fedify/vocab-runtime2.0.19Package registry (OSV)
npm:@fedify/vocab-runtime2.1.15Package registry (OSV)
npm:@fedify/vocab-runtime2.2.4Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:12026-07-09

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+28 d
  3. TodayNov 10, 2026+152 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-6285757 days apartFedify: Server-Side Request Forgery in getNodeInfo() Allows Access to Internal Network Resources
    35Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
low · data or configuration can be modified
Availability
low · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
Low
Availability impact
Low

Weakness class (CWE)

CWE-918 · Server-Side Request Forgery (SSRF)

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records