VulnerabilityPublished 14 Sep 2026

CVE-2026-55253: langchain-mongodb · Improper Neutralization of Special Elements in Data Query Logic

Affects langchain-mongodbSource CVE Database V5

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Not known to be exploited · CVSS 7.7 High : upgrade to 0.4.0 soon.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

7.7High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.4.0, 0.3.0

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 Sep 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 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade langchain-mongodb and langgraph-store-mongodb and langchain-ai/langgraph-store-mongodb to 0.4.0; langgraph-checkpoint-mongodb and langchain-ai/langgraph-checkpoint-mongodb to 0.3.0.

Affected software

Product	Affected	Fixed in
langchain-ailangchain-mongodb	Affected <0.4.0	Fixed in 0.4.0
langchain-ailanggraph-checkpoint-mongodb	Affected <0.3.0	Fixed in 0.3.0
langchain-ailanggraph-store-mongodb	Affected <0.4.0	Fixed in 0.4.0
GitHublangchain-ai/langgraph-checkpoint-mongodb`pkg:github/langchain-ai/langgraph-checkpoint-mongodb`Other threats	Affected <0.3.0	Fixed in 0.3.0
GitHublangchain-ai/langgraph-store-mongodb`pkg:github/langchain-ai/langgraph-store-mongodb`Other threats	Affected <0.4.0	Fixed in 0.4.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade to langgraph-checkpoint-mongodb version 0.3.0 or later and langgraph-store-mongodb version 0.4.0 or later, where this issue is fixed. Until upgraded, avoid using user-controlled filter dictionaries in MongoDB queries or ensure that keys prefixed with '$' are properly sanitized or rejected. No other mitigation or temporary fix is indicated.

Description

LangChain MongoDB provides integrations between MongoDB, Atlas, LangChain, and LangGraph. Prior to langgraph-checkpoint-mongodb 0.3.0 and langgraph-store-mongodb 0.4.0, MongoDBSaver.list(), MongoDBSaver.alist(), and MongoDBStore.search() incorporate filter dictionaries into MongoDB queries without recursively rejecting keys prefixed with $. An authenticated caller who controls a filter argument through HTTP query parameters, request body fields, or agent tool arguments can inject MongoDB Query Language operators such as $regex or $where. In a multi-tenant deployment that uses the filter to enforce per-user or per-tenant isolation, injected operators can bypass intended equality filtering and expose other tenants' checkpoint or store data. Filters constructed entirely from trusted server-side values have lower practical risk. This issue is fixed in langgraph-checkpoint-mongodb 0.3.0 and langgraph-store-mongodb 0.4.0.

Impact

An authenticated user can exploit this vulnerability to inject MongoDB query operators, bypassing intended per-user or per-tenant filtering controls. This can lead to unauthorized access to checkpoint or store data belonging to other tenants in a multi-tenant deployment. There is no indication of impact on data integrity or availability. Filters constructed solely from trusted server-side values are less at risk.

Summary

The vulnerability arises from improper neutralization of special elements in data query logic (CWE-943) within langchain-mongodb. Functions MongoDBSaver.list(), MongoDBSaver.alist(), and MongoDBStore.search() accept filter dictionaries that are incorporated into MongoDB queries without recursively rejecting keys starting with '$'. An authenticated attacker controlling these filters via HTTP parameters or agent tool arguments can inject MongoDB Query Language operators such as $regex or $where. In multi-tenant environments relying on these filters for tenant isolation, this can lead to bypassing equality filters and unauthorized data exposure. The vulnerability is addressed in langgraph-checkpoint-mongodb 0.3.0 and langgraph-store-mongodb 0.4.0.

CWE-943Improper Neutralization of Special Elements in Data Query Logic (opens in a new tab)
Class weakness
The product generates a query intended to access or manipulate data in a data store such as a database, but it does not neutralize or incorrectly neutralizes special elements that can modify the intended logic of the query.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V1.5.1 (opens in a new tab)
Attack patterns
NoSQL Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Sep 2026, 17:46 UTC

WeaknessesCWE-943

Technical details

References

Community reviews

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