What is the CVSS score of CVE-2026-25478?

CVE-2026-25478 has a CVSS 3.1 base score of 7.4 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for CVE-2026-25478?

Yes, a public proof-of-concept exploit is available for CVE-2026-25478. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-25478?

Within 24 hours: Inventory all systems running Litestar and identify those with versions <2.20.0; prioritize public-facing APIs. Within 7 days: Apply vendor patch to 2.20.0 or later on all affected systems, beginning with production environments handling sensitive data. Within 30 days: Conduct CORS configuration audits to verify allowlist values are correctly specified and test origin validation post-patching.

Litestar CVE-2026-25478

Q: Which versions of Litestar are affected by CVE-2026-25478?

A vulnerability in Litestar's CORS validation (CVE-2026-25478) could allow attackers to bypass origin restrictions and access APIs from unauthorized domains, potentially exposing sensitive data or…. A patch is available.

HIGH

Permissive Cross-domain Security Policy with Untrusted Domains (CWE-942)

2026-02-09 security-advisories@github.com

GHSA-2p2x-hpg8-cqp2

Information Disclosure Litestar

7.4

CVSS 3.1 · GitHub Advisory

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Craft malicious origin with regex metacharacters
Exploit

Send CORS preflight request
Execution

Bypass origin validation via regex injection
Impact

Access restricted cross-origin resources

Vulnerability Assessment

Weakness	CWE CWE-942 OWASP Top 10:2025 A02:2025 - Security Misconfiguration ASVS 5.0 V13 - Configuration CORS policy restriction
Exploitation Conditions	Litestar ASGI framework versions prior to 2.20.0 with CORSConfig.allowed_origins_regex enabled. Attacker must trick user into visiting malicious website (UI:R). No authentication required.
Impact	CVSS 7.4 (HIGH). Attack vector: Network. Complexity: Low. Privileges required: None. User interaction: Required. Public exploit/POC available.
Exploit ScenarioDerived	An attacker could exploit this vulnerability to compromise the affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Litestar ASGI framework versions before 2.20.0 fail to properly escape regex metacharacters in CORS origin validation, allowing attackers to bypass origin restrictions through crafted malicious origins. This configuration flaw affects cross-origin request filtering and enables unauthorized cross-origin access. Public exploit code exists for this vulnerability.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 21:54 CVSS 7.4

RemediationAI

A vendor patch is available — apply it immediately. Fixed in version 2.20.0.. Restrict network access to the affected service where possible.

Affected Packages

pypi litestar fix: 2.20.0

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in pypi

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Affects Litestar. Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. Prior to 2.20.0, CORSConfig.allowed_origins_regex is constructed using a regex built from configured allowlist values and used with fullmatch() for validation. Because metacharacters are not escaped, a malicious origin can match unexpectedly. The check relies on allowed_origins_regex.fullmatch(origin). This vulnerability is fixed in 2.20.0.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

GitHub Advisory PRIMARY 7.4 HIGH

AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Lifecycle Timeline

PoC Detected

Feb 17, 2026 - 15:15 vuln.today

Public exploit code

Patch released

Feb 17, 2026 - 15:15 nvd

Patch available

CVE Published

Feb 09, 2026 - 20:15 nvd

HIGH 7.4

DescriptionGitHub Advisory

Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. Prior to 2.20.0, CORSConfig.allowed_origins_regex is constructed using a regex built from configured allowlist values and used with fullmatch() for validation. Because metacharacters are not escaped, a malicious origin can match unexpectedly. The check relies on allowed_origins_regex.fullmatch(origin). This vulnerability is fixed in 2.20.0.

Executive ViewAI

Why It Matters

A vulnerability in Litestar's CORS validation (CVE-2026-25478) could allow attackers to bypass origin restrictions and access APIs from unauthorized domains, potentially exposing sensitive data or enabling cross-site attacks. Organizations using Litestar versions prior to 2.20.0 are immediately at risk, particularly those relying on CORS allowlisting for security boundaries.

Business Impact: High

Compensating Controls

Apply vendor patch. If immediate patching is not feasible: implement Web Application Firewall (WAF) rules to inspect and enforce strict Origin/Referer header validation; restrict Litestar instances to internal networks only; disable CORS if not required; monitor for suspicious cross-origin requests in access logs.

Threat Intelligence Overview

EPSS Score

0.0%

Top 98% exploitable

Exploit

POC

Public exploit code exists

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available Yes

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

Poc

System Exposure· derived

Open

Automatable· derived

Human Impact

High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +37

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.