CVE-2026-55450

CRITICALPre-NVD 9.39.3—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 1.2%, top 34% 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
Elevated
9.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.2%CVSS: 9.3Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, unauthenticated users can upload any amount of data to the server without any limitations. No need for any prior knowledge, only network access to Langflow. This can lead to space exhaustion on the server. In addition, in the response, the absolute path of the uploaded file is reported to the attacker, which is an information leak that can assist in chaining other primitives. This vulnerability is fixed in 1.9.1.

CVSS v3
9.3
EG Score
9.3CRITICALmedium confidence
EG Risk
62
EG Risk 62/100

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
Severity93% × 45%
Exploitation40% × 40%
Automatability30% × 15%
EPSS PROB
1.2%
EPSS %ILE
67th
KEV
Not listed

Published

June 17, 2026

Last Modified

June 24, 2026

Advisory Details (2)

Auto-updated Oct 8, 2026
🔬 Proof of concept available. Patch available. Sources: github_pr, github.
githubMentions a patch (unverified)🟡 PoC Available

Unauthenticated file upload leads to DoS (space exhaustion) and information leak · Advisory · langflow-ai/langflow · GitHub

https://github.com/langflow-ai/langflow/security/advisories/GHSA-x223-p2gf-v735
github_pr

fix(security): require auth on deprecated /api/v1/upload/{flow_id}

Fix merged in langflow-ai/langflow PR #12831 on 2026-04-22 — awaiting tagged release

https://github.com/langflow-ai/langflow/pull/12831

Vendor Advisories for CVE-2026-55450(1)

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

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
langflow0.0.31 ... 1.9.0 (294 versions)
  • every version up to 1.9.1: fixed in 1.9.1
—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 28× 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.

Showing the most recent 100 of 134 total refreshes for this CVE.

  1. 2026-10-10 20:00 UTCEPSS rescore
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  1. 2026-09-13 16:47 UTCEPSS rescore
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  74. 2026-07-19 02:29 UTCEPSS rescore
  75. 2026-07-18 10:04 UTCEPSS rescore

Public detection templates

(1 reference)

A public Nuclei detection template is referenced for this CVE. A detection template checks whether a system is affected; it is not necessarily exploit code.

  • Nucleihttp/cves/2026/CVE-2026-55450.yaml
    Published Jul 31, 2026

    Langflow < 1.9.1 - Unauthenticated File Upload

    Open source ↗

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-55450?
CVE-2026-55450 is a critical vulnerability published on June 17, 2026. Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, unauthenticated users can upload any amount of data to the server without any limitations. No need for any prior knowledge, only network access to Langflow. This can lead to space exhaustion on the…
When was CVE-2026-55450 disclosed?
CVE-2026-55450 was first published on June 17, 2026, with the most recent update on June 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55450 actively exploited?
CVE-2026-55450 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.2% probability of exploitation in the next 30 days (67th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55450?
CVE-2026-55450 has a CVSS base score of 9.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55450?
A fix for CVE-2026-55450 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-55450 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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