CVE-2026-4148: high-severity vulnerability in MongoDB Server
ExpressionContext use-after-free in classic engine $lookup and $graphLookup aggregation operators
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.3%
A use-after-free vulnerability can be triggered in sharded clusters by an authenticated user with the read role who issues a specially crafted $lookup or $graphLookup aggregation pipeline.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
MongoDB Inc · MongoDB ServerRelated CVEs — MongoDB Server
In the same product, most dangerous first.
CVE-2026-25611HIGHPre-Authentication Memory Exhaustion Denial of Service in MongoDB ServerEPSS 0.9%CVE-2025-0755HIGHMongoDB C Driver bson library may be susceptible to buffer overflowEPSS 0.8%CVE-2024-8305MEDIUMMongoDB Server secondaries may crash due to forced index constraintsEPSS 0.6%CVE-2024-10921MEDIUMImproper neutralization of null bytes may lead to buffer over-reads in MongoDB ServerEPSS 0.6%CVE-2024-3372HIGHMongoDB Server may have unexpected application behaviour due to invalid BSONEPSS 0.5%CVE-2025-6709HIGHPre-Authentication Denial of Service Vulnerability in MongoDB Server's OIDC AuthenticationEPSS 0.5%