ExploitedNot in CISA KEV yetFix available

CVE-2026-5027

Q: Is CVE-2026-5027 actively exploited?

Active exploitation of CVE-2026-5027 has not been confirmed. Its EPSS score was 4.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2026-5027?

CVE-2026-5027 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Exploitation confirmed. First attested on 2026-06-10 by GCVE · kevintel, GCVE · shadowserver.

Published2026-03-27
Fixed in1.9.0
WeaknessCWE-22

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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 ('../').

Timeline

dates in UTC

2026-03-2715:17CVE publishedNVD
2026-06-1016:20Listed as exploited by GCVEGCVE
2026-06-1016:20Exploitation first reportedGCVE
2026-10-2319:23First public proof of conceptPoC-in-GitHub

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-5027?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-5027?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Langflow

Branch	Affected	Fixed in	Source
1.9	< 1.9.0	1.9.0	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Langflow to 1.9.0

Advisories and patches

www.tenable.comVendor Advisory

Detection

read 2026-10-23 19:25 UTC

Nuclei template: none so far
Exploit-DB: EDB-52659
Proof-of-concept repositories: 8 repositories, unverifiedyahiahamza/CVE-2026-5027min8282/CVE-2026-5027EQSTLab/CVE-2026-50270xBlackash/CVE-2026-5027Layer-6/CVE-2026-5027-Langflow

Sources

NVDCVE recordread 2026-10-23
GCVEexploitation2026-06-10
CISA-ADPSSVC decisionnone2026-03-27
OpenCVESSVC decisionnone—
CNACVSS 3.18.8read 2026-10-23
CNAweakness (CWE)CWE-22read 2026-10-23
FIRST EPSSEPSS score4.8 %2026-10-22
PoC-in-GitHubproof of concept8read 2026-10-23
Exploit-DBdetectionread 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Published: 2026-03-27
Last Modified: 2026-08-18
NVD status: Analyzed

Frequently asked questions

What is CVE-2026-5027?

Is CVE-2026-5027 actively exploited?

Active exploitation of CVE-2026-5027 has not been confirmed. Its EPSS score was 4.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-5027?

CVE-2026-5027 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

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