CVE-2026-5027
Confirmed PUBLISHEDLangflow - Path Traversal Arbitrary File Write via upload_user_file
Not yet in CISA KEV
Recommended Action
Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.
At a Glance
The 'POST /api/v2/files' endpoint does not sanitize the 'filename' parameter from the multipart form data, allowing an attacker to write files to arbitrary locations on the filesystem using path traversal sequences ('../').
- CVE Published
- Mar 27, 2026
- Exploitation Reported
- Jun 10, 2026
- CVSS
- 8.8 High
- EPSS
- 31.4%
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| langflow-ai |
langflow
|
0 |
Affected |
CVE References
- tenable.com/security/research/tra-2026-26 tenable.com · CVE Record https://www.tenable.com/security/research/tra-2026-26
Recommended Actions
- Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.
- Review sensor telemetry for request paths, attacker IPs, and payload patterns that may inform detection and exposure validation.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| TheHackerNews First | 2026-06-10 16:20 UTC |
| BleepingComputer | 2026-06-10 22:20 UTC |
| The Shadowserver | 2026-07-10 00:00 UTC |
| KEVIntel | 2026-07-10 15:15 UTC |
Operational indicators for this CVE are listed on the Detection tab.
Observed Exploitation Attempts
Exploitation attempts against this vulnerability observed first-hand by KEVIntel private honeypots over the last 30 days.
- Attempts Observed
- 3
- Unique Attacker IPs
- 2
- Attacker Countries
- 🇵🇱 🇺🇸
- Sensors Observed
- 1
Exploitation Attempts Over the Last 11 Days
First observed (all time) 2026-07-10 15:10 UTC · Last observed 2026-07-16 20:19 UTC
See more exploitation detail
- Pro — sensor software/region breakdown and 24h/7d window summaries.
- Enterprise — raw attacker IPs, request paths, User-Agents, and payloads.
Indicators of Compromise (IoCs)
Attacker IP IoCs observed in KEVIntel sensors are available to Pro and Enterprise accounts on the Detection tab and through the Pro API.
Learn about Pro API accessObserved Detection Signals (30d)
Aggregate counts from KEVIntel sensor telemetry for this CVE.
- Distinct request paths
- 1
- Distinct User-Agents
- 3
The specific request paths and User-Agents attackers are using are available on Pro and Enterprise plans.
Scanner Artifacts
Nuclei and Metasploit references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-5027.yaml | Jun 11, 2026 |
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploitation Status
Exploited in the wild
Recorded 2026-06-10 16:20:36 UTC · TheHackerNews
Active exploitation observed
Recorded 2026-07-10 15:10:26 UTC · KEVIntel sensor
Proof of concept available
Recorded 2026-04-02 10:46:45 UTC · GitHub
Weaknesses (CWE)
-
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-5027.yaml | Jun 11, 2026 |
Recent Mentions
BleepingComputer · Jun 10, 2026
Attackers are actively exploiting CVE-2026-5027, a high-severity path traversal vulnerability in the AI development platform Langflow, to write arbitrary files on exposed servers. [...]
TheHackerNews · Jun 10, 2026
A high-severity security flaw in Langflow, an open-source low-code platform to build artificial intelligence (AI) applications, has come under active exploitation in the wild, according to findings from VulnCheck. The vulnerability in question is CVE-2026-5027 (CVSS score: 8.8), a case of path traversal that could allow an attacker to write files to arbitrary locations. "The 'POST /api/v2/
TheHackerNews · Jun 10, 2026
A high-severity unpatched security flaw in Langflow, an open-source low-code platform to build artificial intelligence (AI) applications, has come under active exploitation in the wild, according to findings from VulnCheck. The vulnerability in question is CVE-2026-5027 (CVSS score: 8.8), a case of path traversal that could allow an attacker to write files to arbitrary locations. "The 'POST /
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2026-06-10 19:18:56 UTC · 0 stars
github · Created 2026-04-02 10:46:45 UTC · 4 stars
CVE-2026-5027 - Langflow Path Traversal to Remote Code Execution (CVSS 8.8)
nuclei · Created Unknown
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
15:10 UTC 9 days ago15:10 UTC · 9 days ago
Observed by KEVIntel sensors
Evidence-backed exploitation signal
-
15:10 UTC 9 days ago15:10 UTC · 9 days ago
Indicators of compromise added (2)
Indicators of compromise recorded
-
00:00 UTC 9 days ago00:00 UTC · 9 days ago
KEV confirmed by The Shadowserver
Exploitation attested by an external source
-
04:30 UTC about 1 month ago04:30 UTC · about 1 month ago
Nuclei template available
Scanner coverage available
-
22:20 UTC about 1 month ago22:20 UTC · about 1 month ago
KEV confirmed by BleepingComputer
Exploitation attested by an external source
-
16:20 UTC about 1 month ago16:20 UTC · about 1 month ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
10:46 UTC 4 months ago10:46 UTC · 4 months ago
Public PoC available
Public proof-of-concept code published
-
14:54 UTC 4 months ago14:54 UTC · 4 months ago
CVE published
Vulnerability disclosed publicly
-
14:51 UTC 4 months ago14:51 UTC · 4 months ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2026-5027
{
"cve_id": "CVE-2026-5027",
"title": "Langflow - Path Traversal Arbitrary File Write via upload_user_file",
"affected_vendor": "langflow-ai",
"affected_product": "langflow",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 8.8,
"epss_score": 0.31405,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": true
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}