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Fencer Intel
medium 6.5

CVE-2026-35038 json

signalk-server: Arbitrary Prototype Read via `from` Field Bypass

published 7mo ago modified 3mo ago also GHSA-qh3j-mrg8-f234 , EUVD-2026-18396

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 24%
public exploits
0
none known

Summary

Signal K Server is a server application that runs on a central hub in a boat. Prior to version 2.24.0, there is an arbitrary prototype read vulnerability via `from` field bypass. This vulnerability allows a low-privileged authenticated user to bypass prototype boundary filtering to extract internal functions and properties from the global prototype object this violates data isolation and lets a user read more than they should. This issue has been patched in version 2.24.0.

Patch / fix

  • npm signalk-server 2.24.0
  • signalk signal_k_server 2.24.0

Is CVE-2026-35038 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
7mo ago

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/SignalK/signalk-server/security/advisories/GHSA-qh3j-mrg8-f234 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 2.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
CNA 4.0 2.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/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 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
npm signalk-server
<2.24.0
2.24.0

Affected products

  • SignalK signalk-server

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-125 Out-of-bounds Read
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.