CVE-2026-120811: Use-After-Free in MongoDB Server Classic Query Engine Plan Cache Leads to Information Disclosure and Denial of Service
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-11 15:49 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
A use-after-free issue exists in the MongoDB server’s classic query engine plan cache. Under certain query conditions, an unowned reference to data from an earlier command can be retained in cached plan statistics. After the originating memory is freed, a subsequent diagnostic command serializing those statistics can read freed heap memory, potentially returning sensitive server process memory contents to the authenticated client. Under certain heap reuse conditions, this may also cause the server to crash.
Description quoted from the CVE record (assigned by mongodb, published 2026-11-10).
Weakness: CWE-416: Use After Free
How it can be exploited
Exploitable over the network with low attack complexity only when specific conditions are present needing low privileges and no user interaction. Impact: confidentiality high, integrity none, availability low. CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N
Public exploit evidence (Exploit Observer)
Exploit Observer has no public exploit code naming this CVE. Check Exploit Observer for anything new.
Live scores
- EPSS
- 0.003
low predicted chance of attack - VEDAS
- 0.045
little exploit evidence - On CISA KEV
- Not listed
- Detection rule
- No public rule yet
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| MongoDB Server | from 9.0.0 before 9.0.7 from 8.3.0 before 8.3.16 from 8.0.0 before 8.0.37 from 7.0.0 before 7.0.48 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
Fixed versions stated in the CVE record: 9.0.7, 8.3.16, 8.0.37, 7.0.48.
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
Advisories on this CVE
References
Other references
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.
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