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No exploitation reportedAwaiting NVD analysis

CVE-2026-120803

MongoDB SBE $locf Window Accumulator Use-After-Free Enables Heap OOB Read and Server Crash

No exploitation reported by the sources we read.

  • Published2026-11-10
  • WeaknessCWE-416

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A use-after-free issue exists in MongoDB’s SBE (Slot-Based Execution) implementation of a window function accumulator used by certain $setWindowFields aggregation pipelines. Under specific conditions, the accumulator can retain a dangling pointer to memory that has since been freed. When this stale pointer is later dereferenced during serialization of the carried-forward value, it can result in a heap out-of-bounds read that may expose adjacent heap contents and crash the mongod server. An authenticated user with readWrite privileges on a database can trigger this issue by crafting a specific aggregation pipeline.

Timeline

dates in UTC
  1. 2026-11-1020:02CVE publishedCNA

Versions per branch

Products declared by the CNA

As mongodb, the CNA that assigned this CVE, declared them in the CVE record; versions as written. NVD lists no product for this CVE yet: this is the only product data so far.

  • MongoDB Serverother versions: not affected
    Affected
    • ≥ 9.0.0, < 9.0.7fixed in 9.0.7semver
    • ≥ 8.3.0, < 8.3.16fixed in 8.3.16semver

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-10

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-120803 yet.

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H
CVSS 4.0 vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published
2026-11-10
Last Modified
2026-11-10
NVD status
Awaiting Analysis
GitHub Advisory
GHSA-xqmg-xhh6-75p8

Frequently asked questions

What is CVE-2026-120803?

A use-after-free issue exists in MongoDB’s SBE (Slot-Based Execution) implementation of a window function accumulator used by certain $setWindowFields aggregation pipelines. Under specific conditions, the accumulator can retain a dangling pointer to memory that has since been freed. When this stale pointer is later dereferenced during serialization of the carried-forward value, it can result in a heap out-of-bounds read that may expose adjacent heap contents and crash the mongod server. An authenticated user with readWrite privileges on a database can trigger this issue by crafting a specific aggregation pipeline.

Is CVE-2026-120803 actively exploited?

Active exploitation of CVE-2026-120803 has not been confirmed.

What is the CVSS score for CVE-2026-120803?

CVE-2026-120803 has a CVSS v3 base score of 7.1 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H.

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