CASCACascade Atlas

Evidence dossier

CVE-2025-34291

Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE

79.8–96.3Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

Langflow versions up to and including 1.6.9 contain a chained vulnerability that enables account takeover and remote code execution. An overly permissive CORS configuration (allow_origins='*' with allow_credentials=True) combined with a refresh token cookie configured as SameSite=None allows a malicious webpage to perform cross-origin requests that include credentials and successfully call the refresh endpoint. An attacker-controlled origin can therefore obtain fresh access_token / refresh_token pairs for a victim session. Obtained tokens permit access to authenticated endpoints — including built-in code-execution functionality — allowing the attacker to execute arbitrary code and achieve full system compromise.

State
PUBLISHED
Published
Dec 5, 2025
Updated
Jul 14, 2026
Evidence coverage
72%
CISA KEVCatalog member

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

FIRST EPSS78.89%

2026-07-18 · v2026.06.15 · percentile 99.6%

Source stateConflict visible

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

VulnCheckoriginal assertion
container

Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE

CISA KEVoriginal assertion
observed_exploitation

Langflow Origin Validation Error Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.788900000000; percentile 0.995510000000

Applicability

Cited product scope

Trace impact →
LangflowLangflow
[{"status": "affected", "version": "0", "versionType": "semver", "lessThanOrEqual": "1.6.9"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:langflow:langflow:*:*:*:*:*:*:*:*; end including 1.6.9supported

Assessments

CVSS by origin

8.8
nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.4
disclosure@vulncheck.comCVSS 4.0 · role SecondaryCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
9.4
VulnCheckCVSS 4.0 · role unknownCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.