CVE-2025-12119: 
MongoDB vulnerability analysis and mitigation

CVE-2025-12119 is an expired pointer dereference vulnerability in the MongoDB C Driver and PHP Driver that causes a mongoc_bulk_operation_t to read invalid memory when large options are passed. It was disclosed on November 18, 2025, and affects MongoDB C Driver versions 1.9.0–1.30.5 and 2.0.0–2.1.1, as well as MongoDB PHP Driver (mongodb/mongodb-extension) versions prior to 1.21.2. The vulnerability carries a CVSS v4.0 base score of 6.9 (Medium) as assigned by MongoDB, Inc., and a CVSS v3.1 base score of 3.3 (Low) per NVD enrichment (Github Advisory, NVD).

The root cause is classified as CWE-825 (Expired Pointer Dereference): when large options are supplied to a mongoc_bulk_operation_t, the driver dereferences a pointer to memory that has already been freed or is otherwise no longer valid, resulting in an out-of-bounds read. The flaw resides in write command options handling within libmongoc, as confirmed by the fix description in both the 1.30.6 and 2.1.2 release notes. Exploitation requires local access and low privileges — an attacker or malicious application must be able to invoke bulk operation APIs with crafted oversized option documents. A specific commit fixing the issue in the PHP driver is referenced as fa5b433, and the corresponding C driver fix is commit 775998df7c67 (Github Advisory, C Driver 1.30.6, C Driver 2.1.2).

Successful exploitation could allow a local attacker with low privileges to read sensitive contents from process memory, potentially exposing credentials, query data, or other confidential information handled by the MongoDB driver. There is also a low availability impact, as the invalid memory read could cause application instability or crashes. Integrity is not affected, and there is no evidence of lateral movement potential or impact on subsequent systems (Github Advisory, NVD).

There is no public proof-of-concept exploit and no evidence of in-the-wild exploitation at this time. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score is approximately 0.007% (1st percentile), indicating a very low probability of exploitation in the near term. No threat actor attribution has been reported (Github Advisory, Feedly).

MongoDB has released patched versions addressing this vulnerability. Users should upgrade to the following:

• MongoDB C Driver: version 1.30.6 (for the 1.x branch) or 2.1.2 (for the 2.x branch)
• MongoDB PHP Driver (mongodb/mongodb-extension): version 1.21.2, which bundles libmongoc 1.30.6

No configuration-based workaround is documented; upgrading is the recommended remediation. Additionally, limiting local system access and implementing strict input validation for bulk operation options can reduce exposure until patching is possible (C Driver 1.30.6, C Driver 2.1.2, PHP Driver 1.21.2).