Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 0.52% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-56400High confidence
open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation
open-webui · open-webui
Official source article: GitHub GHSA-6XCP-7MPR-M7WM ↗. Check the applicable product and release in the original source.
9.0CriticalCVSS 4.0
Within 72 hours
Patch availableCritical technical impact and a public exploit reference; no CISA KEV confirmation is currently recorded.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs open-webui open-webui and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Critical technical impact and a public exploit reference; no CISA KEV confirmation is currently recorded.
Patch available01
What, why and how
open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with allow_origins=* and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests from attacker-controlled websites when an admin user visits them.
What
open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with allow_origins=* and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests from attacker-controlled websites when an admin user visits them.
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 when the stated preconditions are met. If successful, the issue may execute code or commands in the affected security context.
What
open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with allow_origins=* and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests from attacker-controlled websites when an admin user visits them.
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 when the stated preconditions are met. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
- Likely attack path
- a network path → Insufficient Session Expiration → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- Passive interaction required
- Attack complexity
- High: exploitation depends on specific conditions
- Security boundary
- Not a CVSS 4.0 base metric
- 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:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIPassiveUser interaction: A user must unknowingly interact with the vulnerable system.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCHighSubsequent-system confidentiality: A successful attack can cause a major loss.SIHighSubsequent-system integrity: A successful attack can cause a major loss.SAHighSubsequent-system availability: A successful attack can cause a major loss.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
03
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
- open-webui: < 0.3.14
- Fixed
- open-webui: 0.3.14
- 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.
04
Evidence and provenance
Published 15 Jul 2026 · Last source change 15 Jul 2026, 18:33 UTC · CWE-613 · Insufficient Session Expiration
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-44629
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
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
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.