CVE-2026-106437: Mongo c driver · The BSON buffer-reservation API in the MongoDB C Driver can record a length smaller
Affects mongo-c-driverSource GCVE Database
Not known to be exploited · CVSS 5.9 Medium.
Data as of 28 Oct 2026, 22:31 UTC
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10mongo-c-driverpkg:deb/ubuntu/mongo-c-driver?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSmongo-c-driverpkg:deb/ubuntu/mongo-c-driver?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu Pro 24.04 LTSmongo-c-driverpkg:deb/ubuntu/mongo-c-driver?arch=source&distro=esm-apps/nobleOther threats | Affected
| Fixed in– |
Ubuntu Pro 22.04 LTSmongo-c-driverpkg:deb/ubuntu/mongo-c-driver?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTSmongo-c-driverpkg:deb/ubuntu/mongo-c-driver?arch=source&distro=esm-apps/focalOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
The BSON buffer-reservation API in the MongoDB C Driver can record a length smaller than the five-byte BSON minimum. Later append or comparison operations can underflow unsigned length calculations and read or write outside the document buffer. An actor who can influence the length supplied by an embedding application can cause the application to terminate or read or corrupt adjacent process memory. Reaching this issue requires the application to pass an undersized value to bson_reserve_buffer and then perform an affected operation.