Quick answers
- Is CVE-2026-106436 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-106436 being exploited in the wild.
- How severe is CVE-2026-106436?
- Medium severity, with a CVSS score of 4.8, published 8 October 2026.
- Which products and versions are affected?
- MongoDB PHP Driver prior to 1.21.11, 2.1.11, 2.5.4.
- Is there a fix for CVE-2026-106436?
- Yes: fixed in 1.21.11, 2.1.11, 2.5.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-106436 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-106436?
- Check whether you run MongoDB PHP Driver at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 1.21.11, 2.1.11, 2.5.4
Technical details
The vulnerability exists in src/phongo_bson_encode.c where multiple libbson append function calls ignore boolean return values, violating libbson's contract that false indicates an invalid child object. When documents exceed 2 GiB or allocation fails, the encoder recurses into uninitialized memory and calls bson_append_document_end, triggering an abort. Separately, scalar append failures silently truncate documents without signaling the application, potentially dropping critical fields like _id or __pclass metadata.
Affected products
- MongoDB PHP Driver prior to 1.21.11, 2.1.11, 2.5.4
Timeline
- 2026-10-08: disclosed
- 2026-10-08: patched