CVE-2026-120803: MongoDB Server · Use After Free
Affects MongoDB ServerSource CVE Database V5
Not known to be exploited · CVSS 7.1 High : upgrade to 9.0.7 or 8.3.16 soon.
Data as of 10 Nov 2026, 20:47 UTC
Thin evidence
One scorer or none| CNA (mongodb) | CVSS 4.0 | 7.1 |
|---|---|---|
| CNA (mongodb) | CVSS 3.1 | 7.1 |
- Patch
- Available – fixed in 9.0.7, 8.3.16
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 10 Nov 2026.
What to do
Upgrade MongoDB Server to 9.0.7 or 8.3.16.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MongoDBMongoDB Server | Affected
| Fixed in
|
| MongoDBMongoDB Server | Affected
| Fixed in
|
AI-suggested
Upgrade MongoDB Server to version 8.3.16 or later, or 9.0.7 or later, where this vulnerability has been fixed. No other mitigations are indicated. Since this is not a cloud service, administrators must apply the patch manually.
Description
CVE-2026-120803 is a use-after-free vulnerability in MongoDB Server's Slot-Based Execution (SBE) implementation of a window function accumulator used by certain $setWindowFields aggregation pipelines. An authenticated user with readWrite privileges can trigger this issue by crafting a specific aggregation pipeline, causing a heap out-of-bounds read that may expose adjacent heap memory and crash the mongod server. The flaw affects MongoDB Server versions 8.3.0 through 8.3.15 and 9.0.0 through 9.0.6. Fixed versions 8.3.16 and 9.0.7 address the issue.