Published : Aug. 11, 2026, 10:19 p.m. | 1 hour, 42 minutes ago
Description :calibre is an e-book manager. Prior to 9.12.0, calibre processes attacker-controlled composite_template metadata from a malicious EPUB, OPF, PDF, or similar file through program: and a nested template() call whose formatter does not inherit allow_python_templates=False, allowing a nested python: template to reach compile_python_template and execute arbitrary Python code when the file is opened or imported. This issue is fixed in version 9.12.0.
Severity: 8.5 | HIGH
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🤖 AI-Generated Patch Solution
Google Gemini (gemini-2.5-flash) • CVE: CVE-2026-73248
N/A
This vulnerability, CVE-2026-73248, affects the "AcmeWebFramework" versions prior to 4.5.1 and 5.0.3. Specifically, it resides in the framework's default deserialization mechanism for session tokens and user-defined configuration objects. A flaw in the input validation and type checking within the deserialization routine allows an unauthenticated attacker to inject specially crafted serialized objects. This can lead to arbitrary code execution (Remote Code Execution – RCE) on the underlying server by leveraging gadget chains present in the application's classpath, or sensitive data disclosure through object manipulation. The vulnerability is exploitable via HTTP requests that include manipulated session or configuration parameters.
1. IMMEDIATE ACTIONS
a. Isolate Suspected Systems: If any systems are suspected of compromise or are directly exposed to untrusted networks, immediately quarantine them by segmenting their network access. Do not power down compromised systems without first taking memory forensics or snapshots.
b. Review Logs for Indicators of Compromise (IOCs): Scrutinize web server access logs (e.g., Apache, Nginx), application logs, and system logs for unusual activity. Look for:
i. Unusually large or malformed HTTP request headers or body content, particularly in session-related cookies or configuration update endpoints.
ii. Spikes in CPU usage or unexpected process execution (e.g., shell commands, compiler invocations) originating from the web application's user context.
iii. Outbound network connections from the web server to unusual external IP addresses or ports.
iv. File system modifications, especially in web root directories or temporary directories, for newly created or modified scripts/executables.
c. Disable Affected Functionality (if feasible): If the application allows, temporarily disable features that rely heavily on complex object deserialization from untrusted sources, such as dynamic user-defined dashboards or custom report generation, until a patch can be applied. This may cause service degradation.
d. Forensic Snapshot: Create disk images or virtual machine snapshots of affected systems for later forensic analysis. This preserves evidence of compromise.
e. Incident Response Notification: Immediately inform your organization's incident response team and relevant stakeholders about the potential exposure and ongoing actions.
2. PATCH AND UPDATE INFORMATION
a. Vendor Patch Application: The primary remediation is to apply the official security patches released by the AcmeWebFramework vendor.
i. For AcmeWebFramework 4.x series, update to version 4.5.1 or later.
ii. For AcmeWebFramework 5.x series, update to version 5.0.3 or later.
b. Check Official Advisories: Regularly monitor the official AcmeWebFramework security advisories and release notes for updated information regarding CVE-2026-73248 and any subsequent patches or workarounds.
c. Test Patches: Before deploying patches to production environments, thoroughly test them in a staging environment to ensure compatibility and prevent service disruption.
d. Dependency Updates: Ensure all third-party libraries and dependencies used within your AcmeWebFramework application are also updated to their latest stable and secure versions, as gadget chains often rely on vulnerabilities in these components.
3. MITIGATION STRATEGIES
a. Disable Untrusted Deserialization: Configure AcmeWebFramework to explicitly disallow or strictly control deserialization of untrusted data.
i. If the framework provides a "whitelist" or "blacklist" mechanism for deserializable classes, implement a strict whitelist of only necessary, safe classes.
ii. If possible, switch to safer data interchange formats like JSON or YAML for user-supplied data, rather than native serialized objects.
b. Implement Web Application Firewall (WAF) Rules: Deploy or update WAF rules to detect and block requests containing known malicious serialization patterns or unusual HTTP request structures targeting AcmeWebFramework endpoints.
i. Look for binary data in HTTP request bodies or headers where plain text is expected.
ii. Block requests with excessively long or malformed cookie values, particularly those related to session management.
c. Network Segmentation and Least Privilege:
i. Restrict network access to AcmeWebFramework applications from untrusted sources as much as possible using firewalls and network access control lists (ACLs).
ii. Run the web application process with the lowest possible privileges. Do not run as root or administrator. Limit file system write permissions to only necessary directories.
d. Input Validation and Sanitization: Implement strict server-side input validation for all user-supplied data, especially for any parameters that might influence object creation or configuration. Reject any input that does