High
Litestar has a CORS origin allowlist bypass due to unescaped regex metacharacters in allowed origins
Type: advisorySources: OSV
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-25478
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 7 Nov 2026, 11:55 UTC · Revision 1
Source evidence
Litestar has a CORS origin allowlist bypass due to unescaped regex metacharacters in allowed origins
core-osv · Original sourcePublished 9 Feb 2026, 18:46 UTC
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.
osv:CVE-2026-25478
Complete source record
{
"id": "934032270249a0596f211f515241e950de0def445d95a0b5fc5e04f453ea5a82",
"url": "https://osv.dev/vulnerability/CVE-2026-25478",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Litestar has a CORS origin allowlist bypass due to unescaped regex metacharacters in allowed origins",
"summary": "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.",
"evidence": "osv:CVE-2026-25478",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-25478",
"aliases": [
"CVE-2026-25478",
"GHSA-2p2x-hpg8-cqp2",
"PYSEC-2026-2195"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/litestar-org/litestar",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "b343d5a3e6310ecb778a406fa26fc8399139c704"
},
{
"fixed": "eb87703b309efcc0d1b087dcb12784e76b003d5a"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:litestar:litestar:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "2.20.0"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "eb87703b309efcc0d1b087dcb12784e76b003d5a"
}
],
"source": "REFERENCES_COMMIT"
},
{
"range": [
{
"fixed": "b343d5a3e6310ecb778a406fa26fc8399139c704"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v2.20.0"
}
]
}
}
],
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],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-25478.json"
}
}
],
"modified": "2026-10-28T02:30:50.705180977Z",
"provider": "osv",
"references": [
"https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0",
"https://github.com/litestar-org/litestar/releases/tag/v2.20.0",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25478.json",
"https://github.com/litestar-org/litestar/security/advisories/GHSA-2p2x-hpg8-cqp2",
"https://nvd.nist.gov/vuln/detail/CVE-2026-25478",
"https://github.com/litestar-org/litestar/commit/eb87703b309efcc0d1b087dcb12784e76b003d5a"
],
"provider_metadata": {
"cwe_ids": [
"CWE-942"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25478.json"
}
},
"related_cves": [
{
"value": "CVE-2026-25478",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 519203,
"published_at": "2026-02-09T18:46:56.445+00:00"
}