Description
An off-by-one error in the BSON bulk document writer in the MongoDB C Driver can write one zero byte immediately past a heap allocation when a document ends at a specific buffer boundary. An actor who can influence the size of documents serialized by an embedding application can corrupt adjacent process memory or terminate the process. Reaching this issue requires the application to use the BSON bulk-writer API and produce a precise cumulative document size.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| MongoDB | C Driver | 0.5.0 – < 1.30.13, 2.0.0 – < 2.5.6 | 1.30.13 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | mongo-c-driver | 2.5.6-1 | — |
| Debian 13 | mongo-c-driver | No fix yet | — |
| Debian 12 | mongo-c-driver | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | mongo-c-driver | No fix yet | — |
| Ubuntu 26.04 LTS | mongo-c-driver | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | mongo-c-driver | No fix yet | — |
| Ubuntu Pro 22.04 LTS | mongo-c-driver | No fix yet | — |
| Ubuntu Pro 20.04 LTS | mongo-c-driver | No fix yet | — |
Advisories 1
- WID-SEC-2026-3830 MongoDB Treiber: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 27, 2026