MongoDB Python Driver: Out-of-bounds read in BSON decoding via a malformed Regex element

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0009, the 1st percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 14:07 UTC First seen by agentprime
2. 31 Oct 2026, 14:07 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-98qm-wvgf-w4cf
• OSV: GHSA-98qm-wvgf-w4cf
• github.com/mongodb/mongo-python-driver/security/advisories/GHSA-98qm-wvgf-w4cf
• nvd.nist.gov/vuln/detail/CVE-2026-106435
• github.com/mongodb/mongo-python-driver/pull/3109
• github.com/mongodb/mongo-python-driver/commit/bb8d4e195275e75bd94ebeffb53cc747d357fcf4
• github.com/mongodb/mongo-python-driver
• github.com/mongodb/mongo-python-driver/releases/tag/4.18.3
• jira.mongodb.org/browse/PYTHON-6110

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.