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NVD / CVE Program· CNA VulnCheck

CVE-2026-100868: Penpot before 2.18.0 Unauthenticated WebSocket Access via MCP Bridge

MediumCVSS 5.3 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.53% (FIRST EPSS).
  • Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: penpot penpot 2.18.0.

Low priority for now. Upgrade to penpot penpot 2.18.0 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

Penpot before 2.18.0 binds the MCP server plugin WebSocket bridge to all network interfaces without authentication in single-user mode. Unauthenticated attackers on adjacent networks can connect to the WebSocket port to impersonate the Penpot browser plugin, intercept task payloads, and return forged results to the MCP client.

Published
Sep 27, 2026
Updated
Oct 8, 2026
EPSS
0.5% · 45th percentile

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
5.3
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

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
  • No public exploit code on record
  • A fix has been released

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

Follow CVE-2026-100868

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 (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • penpot @penpot/mcp

    • up to and including 2.15.4affected · semver

  • penpot penpot

    • before 2.18.0affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
npm@penpot/mcpbefore 2.15.02.15.0

Same product

penpot: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-105691Penpot: Authenticated OS Command Injection in Penpot SVG Exporter via Legacy fill-color
    39Monitor
  • CVE-2026-44986Penpot: Pre-authenticated account takeover via team-invitation token + prepare-register-profile
    39Monitor
  • CVE-2026-45805Penpot: MCP REPL server binds to 0.0.0.0 with unauthenticated /execute endpoint — RCE
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-47665Aug 26, 2026 · Penpot: Stored XSS via comment content, innerHTML renders unsanitized HTML
    34Monitor
  • ← EarlierCVE-2026-47666Aug 26, 2026 · Penpot: Stored XSS via custom font family name injected into a @font-face style rule
    30Monitor
  • Later →CVE-2026-105684Oct 5, 2026 · Penpot: Share-link page-scope escape — comment RPCs leak comment content, author identity, and all page-ids for pages outside the share scope
    17Monitor

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
penpot penpot2.18.0Vendor (CNA)
npm:@penpot/mcp2.15.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

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.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

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

Credits

All researchers

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

Chain candidates

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

  • CVE-2026-1056918 days apartPenpot: Authenticated OS Command Injection in Penpot SVG Exporter via Legacy fill-color
    39Monitor
  • CVE-2026-4580674 days apartPenpot: Authenticated SSRF in remote image import via create-file-media-object-from-url
    30Monitor
  • CVE-2026-1056898 days apartPenpot: SSRF guard bypass via IPv6 transition addresses (NAT64/6to4/Teredo) in webhook delivery and media download
    24Monitor

Not on record for this CVE: public bounty program.

Technical details

Attack conditions

  • Someone on the same network segment 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
Integrity
Availability
Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-1327 · Binding to an Unrestricted IP Address

CVSS vector

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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.

References

Show all references (5 more)

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

All records