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Full vulnerability report · 2026
CVE-2026-82052High confidence

$regexFindAll may crash mongod server when byte-matching multi-byte UTF-8 chars

MongoDB · MongoDB Server

7.1HighCVSS 4.0
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-72939

No EUVD known-exploited evidence

The $regexFindAll expression can be used by an authenticated user who can run aggregation pipeline stages to crash a MongoDB server (mongod). Under certain specific conditions the  regex match can start in the middle of a multi-code-unit character, triggering an assertion during query execution.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
7.1 · CVSS 4.0
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
01

What, why and how

The $regexFindAll expression can be used by an authenticated user who can run aggregation pipeline stages to crash a MongoDB server (mongod). Under certain specific conditions the  regex match can start in the middle of a multi-code-unit character, triggering an assertion during query execution.

What

The $regexFindAll expression can be used by an authenticated user who can run aggregation pipeline stages to crash a MongoDB server (mongod). Under certain specific conditions the  regex match can start in the middle of a multi-code-unit character, triggering an assertion during query execution.

Why

The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

What

The $regexFindAll expression can be used by an authenticated user who can run aggregation pipeline stages to crash a MongoDB server (mongod). Under certain specific conditions the  regex match can start in the middle of a multi-code-unit character, triggering an assertion during query execution.

Why

The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Reachable Assertion → disrupt the affected service
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-617 ↗

CWE-617: Reachable Assertion. The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/AU:Y/R:A

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkDenial of serviceCWE-617
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-72939Official EUVD mapping

The $regexFindAll expression can be used by an authenticated user who can run aggregation pipeline stages to crash a MongoDB server (mongod). Under certain specific conditions the  regex match can start in the middle of a multi-code-unit character, triggering an assertion during query execution.

Official EUVD record ↗
BSI · German · WID-SEC-2026-3320MongoDB: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in MongoDB ausnutzen, um Abfrage- und Zugriffsbeschränkungen zu umgehen, nicht vorgesehene Datensätze oder Dateien auszulesen, zu verändern oder zu löschen sowie unter bestimmten Voraussetzungen MongoDB-Server oder Anwendungen zum Absturz zu bringen und dadurch einen Denial-of-Service zu verursachen.

Official advisory ↗
BSI · German · WID-SEC-2026-3236MongoDB Server: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in MongoDB Server ausnutzen, um erweiterte Berechtigungen, einschließlich Administratorrechte, zu erlangen und beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen oder einen Denial-of-Service-Zustand auszulösen.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1157Multiples vulnérabilités dans MongoDB Server

goDB SERVER-131860 du 08 septembre 2026 https://jira.mongodb.org/browse/SERVER-131860 Bulletin de sécurité MongoDB SERVER-131870 du 08 septembre 2026 https://jira.mongodb.org/browse/SERVER-131870 Bulletin de sécurité MongoDB SERVER-132125 du 08 septembre 2026 https://jira.mongodb.org/browse/SERVER-132125 Bulletin de sécurité MongoDB SERVER-132275 du 08 septembre 2026 https://jira.mongodb.org/browse/SERVER-132275 Bulletin de sécurité MongoDB SERVER-132650 du 08 septembre 2026 https://jira.mongodb.org/browse/SERVER-132650 Bulletin de sécurité MongoDB SERVER-132835 du 08 septembre 2026 https://jira.mongodb.org/browse/SERVER-132835 Référence CVE CVE-2026-82052 https://www.cve.org/CVERecord?id=CVE-2026-82052 Référence CVE CVE-2026-82053 https://www.cve.org/CVERecord?id=CVE-2026-82053 Référence CVE CVE-2026-82054 https://www.cve.org/CVERecord?id=CVE-2026-82054 Référence CVE CVE-2026-82055 https://www.cve.org/CVERecord?id=CVE-2026-82055 Référence CVE CVE-2026-82056 https://www.cve.org/CVERecord?id=CVE-2026-82056 Référence CVE CVE-2026-82057 https://www.cve.org/CVERecord?id=CVE-2026-82057 Référence CVE CVE-2026-82058 https://www.cve.org/CVERecord?id=CVE-2026-82058 Référence CVE CVE-2026-82059 https://www.cve.org/CVERecord?id=CVE-2026-82059 Référence CVE CVE-2026-82060 https://www.cve.org/CVERecord?id=

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
MongoDB Server: 8.3.0 < 8.3.9, 8.0 < 8.0.30, 7.0 < 7.0.41
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 8 Sept 2026 · Last source change 10 Sept 2026, 18:30 UTC · CWE-617 · Reachable Assertion

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-09
European sourceENISA EUVD · EUVD-2026-72939
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enrichment underway

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. ENISA EUVD mappingEUVD-2026-72939 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-72939"}
    ENISA EUVD ↗
  2. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-72939↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-82052 · cve.blacktree.nl