CVE-2026-55253

HIGHPre-NVD 7.77.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 67% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
7.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.7Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
7.7
EG Score
7.7(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity77% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
33%
KEV
Not listed

Published

August 20, 2026

Last Modified

September 14, 2026

Advisory Details (5)

Auto-updated Sep 14, 2026
Patch available. Sources: github, github_pr, github_commit.
github_commit

commit 5465e4d3ea0e (langchain-ai/langchain-mongodb)

Fix landed in langchain-ai/langchain-mongodb commit 5465e4d3ea0e — awaiting tagged release

https://github.com/langchain-ai/langchain-mongodb/commit/5465e4d3ea0ef5c88a666a6442bd853ff4bd70e5
github_commit

commit 240e7ecee432 (langchain-ai/langchain-mongodb)

Fix landed in langchain-ai/langchain-mongodb commit 240e7ecee432 — awaiting tagged release

https://github.com/langchain-ai/langchain-mongodb/commit/240e7ecee432ea006d9fef6ea506bfd2e009a3f4
github_commit Patch Available

commit 14a6cc39e67d (langchain-ai/langchain-mongodb)

Patch available: langchain-ai/langchain-mongodb libs/langgraph-checkpoint-mongodb/v0.4.0 (contains commit 14a6cc39e67d)

https://github.com/langchain-ai/langchain-mongodb/commit/14a6cc39e67d23fd409cd13a9caae2c329df0a09
github_pr Patch Available

[INTPYTHON-961] Reject MQL operator keys in filter dicts to prevent query injection

Patch available: langchain-ai/langchain-mongodb libs/langgraph-checkpoint-mongodb/v0.4.0 (PR #384 merged 2026-05-08)

https://github.com/langchain-ai/langchain-mongodb/pull/384
github Patch Available

NoSQL Operator Injection in MongoDBSaver.list() leading to cross-tenant data exposure · Advisory · langchain-ai/langchain-mongodb · GitHub

https://github.com/langchain-ai/langchain-mongodb/security/advisories/GHSA-533j-2v4q-mw5h

Vendor Advisories for CVE-2026-55253(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(2 across 1 ecosystem)
PyPI(2)
PackageVulnerable rangeFixed inDependents
langgraph-checkpoint-mongodb0.1.0 ... 0.2.2 (11 versions)0.3.0—
langgraph-store-mongodb0.0.1, 0.1.0, 0.1.1, 0.2.0, 0.3.00.4.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 12× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 21:39 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 21:19 UTCEG score recompute
  4. 2026-09-17 19:31 UTCEPSS rescore
  5. 2026-09-16 21:42 UTCEG score recompute
  6. 2026-09-16 14:08 UTCEPSS rescore
  7. 2026-09-16 09:41 UTCEG score recompute
  8. 2026-09-16 05:15 UTCEPSS rescore
  9. 2026-09-14 20:27 UTCEG score recompute
  10. 2026-09-14 20:15 UTCEG score recompute
  11. 2026-09-14 18:35 UTCEG score recompute
  12. 2026-08-20 17:42 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-55253?
CVE-2026-55253 is a high vulnerability published on August 20, 2026. 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…
When was CVE-2026-55253 disclosed?
CVE-2026-55253 was first published in the National Vulnerability Database on August 20, 2026, with the most recent update on September 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55253 actively exploited?
CVE-2026-55253 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 67.1% of all scored CVEs.
What is the CVSS score of CVE-2026-55253?
CVE-2026-55253 has a CVSS v3 base score of 7.7 (NVD).
How do I remediate CVE-2026-55253?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55253, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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