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Fencer Vulns
high 8.3

CVE-2026-49471 json

Serena: Unauthenticated Flask dashboard on fixed port enables DNS rebinding → memory poisoning → RCE

published 2026-07-07 4 mo ago modified 2026-10-25 14 d ago also GHSA-37h2-6p4f-mp3q , PYSEC-2026-3061 , EUVD-2026-42077

cvss
8.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

Serena is a powerful MCP toolkit for coding that provides semantic retrieval and editing capabilities. Prior to v1.5.2, Serena's built-in web dashboard exposes an unauthenticated Flask API on a fixed, predictable port, with no authentication, no CSRF protection, and no Host header validation. A DNS rebinding attack allows a malicious webpage to reach this API from any browser and write arbitrary content to the agent's persistent memory store, which the agent reads and acts on autonomously. Combined with execute_shell_command using shell=True, this creates a remote code execution chain requiring only that the victim visit a malicious webpage while Serena is running. This issue is fixed in version v1.5.2.

Patch / fix

  • pypi serena-agent 1.5.2
  • oraios-ai serena 1.5.2

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
4 mo ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/oraios/serena/security/advisories/GHSA-37h2-6p4f-mp3q referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
OSV 3.1 8.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
GitHub 3.1 8.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi serena-agent
<1.5.2
1.5.2

Affected products

  • oraios serena

Classification

Weakness
  • CWE-306 Missing Authentication for Critical Functionality
  • CWE-352 Cross-Site Request Forgery

References

Sources

Fencer Vulns 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.