CVE-2026-81268: Langflow is vulnerable to authentication bypass and insufficient session expiration

Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available

What, why and how

IBM Langflow OSS 1.0.0 through 1.11.5 could allow a remote authenticated attacker to execute flows and obtain sensitive information due to insufficient session expiration of API keys after user deactivation.

What

Why

According to WASC, Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may obtain information outside the intended access boundary.

What

Why

According to WASC, Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may obtain information outside the intended access boundary.

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path: a network path → Insufficient Session Expiration → obtain information outside the intended access boundary
Attack surface: Network
Privileges required: Low: a basic authenticated account is required
User interaction: None
Attack complexity: Low: no specialised conditions are recorded
Security boundary: Unchanged: impact remains within the vulnerable component's security authority
Weakness ? CWE means Common Weakness Enumeration: a standard category for the underlying weakness.: CWE-613 ↗
CWE-613: Insufficient Session Expiration. According to WASC, Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.
CVSS vector ? CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land: No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.

NetworkCWE-613

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-75777Official EUVD mapping

Official EUVD record ↗

BSI · German · WID-SEC-2026-3239Langflow OSS: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Langflow OSS ausnutzen, um beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren, erweiterte Berechtigungen zu erlangen oder sensible Informationen offenzulegen.

Official advisory ↗

Cyber Security Agency of Singapore · English · CSA-SB-20260916Security Bulletin 16 Sep 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 16 Sep 2026, published on 16 September 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗

JVN iPedia · Japanese · JVNDB-2026-033812langflowにおけるセッション期限に関する脆弱性

IBM Langflow OSS バージョン 1.0.0 から 1.11.5 において、ユーザーが無効化された後に API キーのセッション期限切れ処理が不十分であるため、リモートの認証済み攻撃者がフローを実行し、機密情報を取得できる可能性があります。

Official advisory ↗

Patch and workaround

Operational remediation based on structured source evidence.

Status ? Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.: Patch available
Affected: Langflow OSS: 1.0.0 ≤ 1.11.5
Fixed: IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.11.6 https://pypi.org/project/langflow/
Action: Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround: No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.

Evidence and provenance

Published 10 Sept 2026 · Last source change 12 Sept 2026, 03:55 UTC · CWE-613 · Insufficient Session Expiration

CVE recordCVE.org · 5.2

CVSS sourceCNA

EPSS source

The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.

FIRST · tracked since 2026-09-11

European sourceENISA EUVD · EUVD-2026-75777

Product sourceCNA

Remediation sourceCVE/CNA references

CWE sourceCNA

NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

12 Sep 2026, 03:55 UTC
Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: ibm.com/7286662.
Before
remediation: ibm.com/7286662
After
remediation: ibm.com/7286662 · vendor advisory: ibm.com/7286662
psirt@us.ibm.com ↗
11 Sep 2026, 13:46 UTC
Vendor guidanceAuthoritative vendor guidance changed: added remediation: ibm.com/7286662.
Before
no authoritative guidance recorded
After
remediation: ibm.com/7286662
CNA ↗
11 Sep 2026, 13:46 UTC
Affected versionsThe structured affected or fixed version information changed.
Before
1.0.0 ≤ 1.11.5 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
After
Langflow OSS: 1.0.0 ≤ 1.11.5 · Fixed: IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.11.6 https://pypi.org/project/langflow/
CNA ↗
11 Sep 2026, 13:46 UTC
Remediation statusRemediation status changed from Awaiting fix to Patch available.
Before
Awaiting fix
After
Patch available
CNA ↗
11 Sep 2026, 12:52 UTC
ENISA EUVD mappingEUVD-2026-75777 was added to the official ENISA EUVD mapping for this CVE.
Before
not recorded
After
{"euvdId":"EUVD-2026-75777"}
ENISA EUVD ↗
10 Sep 2026, 21:31 UTC
Catalogue recordCVE added to the BlackTree catalogue.
CNA ↗

2026-09-10CVE published

2026-09-12Fixed release or patch reference recorded

ENISA EUVD · EUVD-2026-75777↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗

Technical terms and abbreviations used in this report

CVE: Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS: Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS: Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE: Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA: CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP: Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD: National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT: A computer security incident response team that publishes warnings or coordinates incident response.
PoC: Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF: Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL: Living off the land: abuse of legitimate tools or system functions during an attack.

Langflow is vulnerable to authentication bypass and insufficient session expiration

Published severity in operational context

Evidence used

Compensating controls

Verification

National CERT insights
?
CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

ENISA European Vulnerability Database

EUVD-2026-75777

What, why and how

Exploit reality and attack path

Official authority intelligence

Patch and workaround

Evidence and provenance

What changed after publication