CVE-2025-3248: Langflow Langflow

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

Yes, if you run Langflow Langflow. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-05-05, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-05-26; treat that as the outer limit, not the target. CISA also lists it as known to be used in ransomware campaigns.
EPSS 100.0%, percentile 100.0: FIRST’s model estimates a 100.0% chance of exploitation activity in the next 30 days, higher than 100.0% of all scored CVEs (very high). EPSS is a probability, not a verdict.
Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
Only applies if your dependency tree includes langflow (PyPI) < 1.3.0, fixed in 1.3.0; langflow-base (PyPI) < 0.3.0, fixed in 0.3.0. Check your lockfile, including transitive dependencies.
Editorial verdict: Check exposure. Langflow Unauthenticated Code Execution (CVE-2025-3248) — Fixed in March 2025 and exploited in the wild since; if any Langflow below 1.3.0 is reachable from the internet, treat it as compromised, not merely unpatched.

What it is

Langflow versions prior to 1.3.0 are susceptible to code injection in the /api/v1/validate/code endpoint. A remote and unauthenticated attacker can send crafted HTTP requests to execute arbitrary code.

From the GitHub advisory

CISA’s summary

Langflow contains a missing authentication vulnerability in the /api/v1/validate/code endpoint that allows a remote, unauthenticated attacker to execute arbitrary code via crafted HTTP requests.

Weakness type: CWE-306, CWE-94.

Product: Langflow Langflow · Assigned by: VulnCheck · Published: 2025-04-07

Affected and fixed versions

Ecosystem	Package	Vulnerable	First fixed
PyPI	`langflow`	< 1.3.0	1.3.0
PyPI	`langflow-base`	< 0.3.0	0.3.0

Vendor	Product	Affected versions (per CVE record)
langflow-ai	langflow	< 1.3.0

Severity scores

Scored by	CVSS	Score	Vector
VulnCheck	3.1	9.8 Critical	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
GitHub	4.0	9.3	`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A`

Attack vector: network (remotely reachable)
Attack complexity: low
Attack requirements: none
Privileges required: none (no login)
User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

CISA KEV: added 2025-05-05; federal due date 2025-05-26. Known ransomware use: Known.
CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
FIRST EPSS (model of 2026-10-21): 99.99% probability of exploitation activity in the next 30 days; percentile 100.0.

Timeline

2025-04-07 — CVE record published by VulnCheck
2025-04-07 — erroneo.us brief: Langflow Unauthenticated Code Execution (CVE-2025-3248)
2025-05-05 — Added to CISA’s Known Exploited Vulnerabilities catalog
2025-05-26 — CISA remediation deadline for US federal agencies
2025-06-17 — GitHub-reviewed advisory GHSA-rvqx-wpfh-mfx7 published (critical)
2026-10-08 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Other references from the CVE record and advisory

github.com github.com
horizon3.ai horizon3.ai
vulncheck.com vulncheck.com
github.com github.com
github.com github.com

All exploited Langflow vulnerabilities · Critical PyPI advisories · Today’s Security Digest