CVE-2026-50813: SQLite Session Extension Information Disclosure Vulnerability

Technical summary

CVE-2026-50813 is an information disclosure vulnerability in SQLite's Session Extension, specifically in the changeset concat and changegroup merge code paths. The vulnerability is rooted in a buffer over-read condition (CWE-126) that exposes memory contents during session merge operations. An unauthenticated local attacker can trigger the flaw through a specially crafted session merge operation, bypassing normal access controls. The attack surface is limited to local access but does not require elevated privileges. Remediation requires updating to a SQLite version that includes Fossil check-in 869a51ae84df or later.

Business impact

Organizations relying on SQLite to store or process sensitive data—including embedded databases in applications, development environments, or edge deployments—face confidentiality risk. The information disclosure could expose database contents, credentials, or application secrets if an attacker gains local system access. The availability impact component suggests that malicious merge operations could degrade database performance or trigger crashes, compounding the risk in production or business-critical scenarios. SQLite's wide deployment in mobile, IoT, and embedded systems means the blast radius is potentially large, though actual risk depends on deployment context and data sensitivity.

Affected systems

The vulnerability affects SQLite versions prior to Fossil check-in 869a51ae84df. Affected systems include any application or service using the SQLite Session Extension for database synchronization or changeset merging. This includes mobile applications, embedded systems, development tools, and any infrastructure relying on SQLite for local data storage or replication. The specific version numbers of affected SQLite releases should be verified against the official SQLite release notes and vendor advisories to determine your organizational exposure.

Exploitability

Exploitability is constrained but realistic. The attack requires local system access—the attacker must be able to interact with the vulnerable SQLite process or database file locally. User interaction is required to trigger the flaw, meaning the attacker must craft a malicious session merge operation and have it executed by a legitimate user or process. There is no known public exploit code, and the vulnerability does not appear on the CISA Known Exploited Vulnerabilities (KEV) catalog, suggesting active exploitation in the wild is not yet documented. However, the simplicity of the trigger mechanism and the prevalence of SQLite make weaponization a near-term risk.

Remediation

Upgrade SQLite to a version that includes Fossil check-in 869a51ae84df or later. Consult the official SQLite release notes and your application vendor for specific version numbers and availability timelines. Interim mitigations include restricting local system access to reduce the attack surface and disabling the Session Extension if it is not actively used. Organizations should test patches in non-production environments before deployment, as SQLite updates may require application recompilation or redeployment depending on how it is integrated.

Patch guidance

Check the official SQLite website and Fossil repository for the release that includes Fossil check-in 869a51ae84df. If you use SQLite through a third-party application or framework, verify patch availability through your vendor's release notes or security advisories. Static linking of SQLite requires application rebuild and redeployment; dynamically linked installations may only require updating the SQLite library. Test the patched version against your application's test suite to ensure Session Extension functionality remains intact and that no regressions are introduced. Establish a testing timeline and deployment schedule aligned with your organization's risk tolerance and business continuity requirements.

Detection guidance

Monitor for suspicious session merge or changeset operations, particularly those that fail or produce unexpected error messages. Enable SQLite's debugging and logging where supported to capture attempted merge operations and their outcomes. On vulnerable systems, intrusion detection signatures can be developed to identify malformed changeset or changegroup data being passed to the Session Extension. Review application logs for repeated session merge failures or memory-related errors that may indicate exploitation attempts. If your systems are air-gapped or do not actively use the Session Extension, verify that it can be safely disabled or that its use is confined to trusted internal processes only.

Why prioritize this

This vulnerability should be prioritized in environments where SQLite stores or processes sensitive data and where local system access is difficult to fully restrict. The combination of information disclosure and availability impact, paired with the ease of triggering the flaw once local access is gained, justifies medium priority. However, organizations with strong local access controls and SQLite deployments handling only non-sensitive data may defer patching. The lack of KEV status and active exploitation does not eliminate the need to patch—it reflects current threat landscape maturity, not the vulnerability's inherent severity.

Risk score, explained

The CVSS 3.1 score of 6.1 (Medium) reflects a local attack vector, low attack complexity, and absence of privilege requirements, balanced against limited confidentiality impact but notable availability impact. The user interaction requirement moderates the score; without it, the severity would climb into the High range. The score appropriately captures the moderate threat level while underscoring that remediation is prudent, not optional, particularly for systems in sensitive data environments.

Frequently asked questions