Serena: Unauthenticated Flask dashboard on fixed port enables DNS rebinding → memory poisoning → RCE (CVE-2026-49471) | HOL Guard CVE

High · CVSS 8.3CVE-2026-49471GHSA-37H2-6P4F-MP3Q

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

Answer in brief

CVE-2026-49471 records a High severity (CVSS 8.3) vulnerability in Serena: Unauthenticated Flask dashboard on fixed port enables DNS rebinding → memory poisoning → RCE. The current sources do not mark it as known exploited. The current feed maps oraios/serena (generic), serena-agent (pip). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 7, 2026Updated Jul 10, 2026Source checked Sep 17, 2026First seen by HOL Jul 7, 2026Material review Jul 10, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.3
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 8.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps oraios/serena (generic), serena-agent (pip). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
oraios/serenageneric	< 1.5.2	Not reported
serena-agentpip	<1.5.2	1.5.2

Recommended response

Check inventory. Check lockfiles and deployed manifests for oraios/serena, serena-agent.
Review the reported fix. Update serena-agent to 1.5.2 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 7, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Jul 10, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 7, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.