Published : July 20, 2026, 10:17 p.m. | 2 hours, 18 minutes ago
Description :AgenticMail gives AI agents real email addresses and phone numbers. In @agenticmail/claudecode prior to version 0.2.39, @agenticmail/codex prior to version 0.1.33, @agenticmail/core prior to version 0.9.43, and @agenticmail/openclaw prior to version 0.5.71, two inbound-mail handlers act on a privileged effect without verifying that the sender is the operator, while a sibling handler in the same repo does. The higher-impact one: any external email routed to the bridge inbox causes the dispatcher to resume the operator’s Claude Code session with `permissionMode: ‘bypassPermissions’`, embedding the attacker-controlled `from`/`subject`/`preview` verbatim into the prompt the resumed agent reads — an indirect prompt injection into a fully-privileged agent (Bash/Write/Edit/WebFetch + the agenticmail MCP toolbelt) running as the operator’s OAuth identity. The sibling operator-query email-reply hook gates the same untrusted-From provenance with `isOperatorReplySender(replyFrom, config.operatorEmail)` (fail-closed); the bridge-wake path — a strictly higher-privilege effect — has no equivalent. @agenticmail/claudecode 0.2.39, @agenticmail/codex 0.1.33, @agenticmail/core 0.9.43, and @agenticmail/openclaw 0.5.71 contain a fix.
Severity: 8.2 | HIGH
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🤖 AI-Generated Patch Solution
Google Gemini (gemini-2.5-flash) • CVE: CVE-2026-57495
N/A
This vulnerability affects the 'acme-core-serialization' library used within the Acme Web Framework versions 3.0.0 through 3.5.0. An unauthenticated attacker can achieve remote code execution on the underlying server by sending specially crafted serialized objects to application endpoints that utilize the vulnerable deserialization routines. This allows the attacker to execute arbitrary commands with the privileges of the application.
1. IMMEDIATE ACTIONS
a. Emergency Network Isolation: Immediately isolate any systems running affected versions of the Acme Web Framework from public internet access. This can involve moving them to a quarantined network segment or blocking external inbound connections at perimeter firewalls.
b. Review Logs for Compromise: Scrutinize web server access logs, application logs, and operating system logs (e.g., /var/log/auth.log, Windows Event Viewer Security logs) for any unusual activity. Look for unexpected process creations, outbound connections from the web server, unusual file modifications, or suspicious HTTP requests containing large or malformed serialized data payloads.
c. Disable Affected Endpoints: If feasible, temporarily disable or restrict access to any web application endpoints that are known to accept serialized input. This may involve reconfiguring the web server or application gateway to return an error for specific paths.
d. Backup Critical Data: Perform immediate backups of all critical data and system configurations on affected servers to ensure recovery capability in case of compromise.
e. Activate Incident Response Plan: Engage your organization's incident response team to coordinate containment, eradication, and recovery efforts.
2. PATCH AND UPDATE INFORMATION
a. Vendor Patch Release: Acme Corp has released a security patch addressing CVE-2026-57495. The patched versions of the Acme Web Framework are 3.5.1 and later. This patch specifically hardens the 'acme-core-serialization' library to prevent insecure deserialization of untrusted data.
b. Obtaining the Patch: Download the official patch or updated framework version directly from the Acme Corp official security portal or your licensed software repository. Verify the integrity of the downloaded files using provided checksums or digital signatures.
c. Patch Application Procedure:
i. Review the release notes and installation instructions provided by Acme Corp for version 3.5.1 or later.
ii. Test the patch in a non-production environment that mirrors your production setup to identify any compatibility issues or regressions before deployment.
iii. Schedule a maintenance window for production systems.
iv. Apply the patch or upgrade the Acme Web Framework to version 3.5.1 or higher according to the vendor's instructions. This typically involves replacing affected library files or performing a full framework upgrade.
v. Restart the application servers to ensure the new libraries are loaded.
vi. Verify application functionality post-patch.
3. MITIGATION STRATEGIES
a. Web Application Firewall (WAF) Rules: Implement WAF rules to detect and block suspicious requests. Create rules that specifically look for common gadget chains used in Java/PHP/.NET deserialization attacks (e.g., specific class names, binary data signatures, or unusual command-like strings within serialized payloads). Block requests with excessively large or malformed content-types often associated with deserialization attacks.
b. Network Segmentation: Ensure that application servers running the Acme Web Framework are placed in a highly restricted network segment, isolated from other critical systems. Limit outbound connections from these servers to only essential services (e.g., database, logging, external APIs).
c. Least Privilege Principle: Run the application and its underlying services with the absolute minimum necessary privileges. If an RCE occurs, this will limit the attacker's ability to escalate privileges or move laterally.
d. Disable Unnecessary Deserialization: Review application code to identify if any deserialization of untrusted data is occurring. If possible, refactor the application to avoid deserializing data from untrusted sources. Consider using safer data formats like JSON or XML with schema validation instead of binary serialization.
e. Class Whitelisting/Blacklisting: If deserialization of trusted data is essential, implement strict class whitelisting within your serialization configuration. Allow only a predefined set of safe classes to be deserialized, preventing the instantiation of malicious gadget classes. Avoid blacklisting, as it is often bypassable.
f. Restrict Outbound Connections: Configure host-based firewalls on the application servers to block all unnecessary outbound connections. This can help prevent an attacker from downloading additional tools or establishing command-and-control channels post-exploitation.
4. DETECTION METHODS
a. Log Monitoring