Keycloak: keycloak: denial of service due to excessive samlrequest decompression
A flaw was found in Keycloak. An unauthenticated remote attacker can trigger an application level Denial of Service (DoS) by sending a highly compressed SAMLRequest through the SAML Redirect Binding. The server fails to enforce size limits during DEFLATE decompression, leading to an OutOfMemoryError (OOM) and subsequent process termination. This vulnerability allows an attacker to disrupt the availability of the service.
- Products
- keycloak
- Affected versions
- Not specified
- Fixed versions
- 26.4.10
- CVEs
- CVE-2026-2575
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 04:20 UTC · Revision 1
Source evidence
Keycloak: keycloak: denial of service due to excessive samlrequest decompression
core-osv · Original sourcePublished 25 Aug 2026, 11:42 UTC
A flaw was found in Keycloak. An unauthenticated remote attacker can trigger an application level Denial of Service (DoS) by sending a highly compressed SAMLRequest through the SAML Redirect Binding. The server fails to enforce size limits during DEFLATE decompression, leading to an OutOfMemoryError (OOM) and subsequent process termination. This vulnerability allows an attacker to disrupt the availability of the service.
osv:BIT-keycloak-2026-2575
keycloak
Fixed versions: 26.4.10
Complete source record
{
"id": "2b43d581d27ee38a1b6f54c588044cf056f4c21171a47b5bf8011c5de3b8fd32",
"url": "https://osv.dev/vulnerability/BIT-keycloak-2026-2575",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Keycloak: keycloak: denial of service due to excessive samlrequest decompression",
"summary": "A flaw was found in Keycloak. An unauthenticated remote attacker can trigger an application level Denial of Service (DoS) by sending a highly compressed SAMLRequest through the SAML Redirect Binding. The server fails to enforce size limits during DEFLATE decompression, leading to an OutOfMemoryError (OOM) and subsequent process termination. This vulnerability allows an attacker to disrupt the availability of the service.",
"evidence": "osv:BIT-keycloak-2026-2575",
"products": [
{
"name": {
"value": "keycloak",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "26.4.10",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "BIT-keycloak-2026-2575",
"aliases": [
"BIT-keycloak-2026-2575",
"CVE-2026-2575",
"GHSA-xv6h-r36f-3gp5"
],
"affected": [
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "26.4.0"
},
{
"fixed": "26.4.10"
}
]
}
],
"package": {
"name": "keycloak",
"purl": "pkg:bitnami/keycloak",
"ecosystem": "Bitnami"
},
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
}
],
"database_specific": {
"source": "https://github.com/bitnami/vulndb/tree/main/data/keycloak/BIT-keycloak-2026-2575.json"
}
}
],
"modified": "2026-10-07T14:30:10.814362493Z",
"provider": "osv",
"references": [
"https://access.redhat.com/errata/RHSA-2026:3947",
"https://access.redhat.com/errata/RHSA-2026:3948",
"https://access.redhat.com/security/cve/CVE-2026-2575",
"https://bugzilla.redhat.com/show_bug.cgi?id=2440149",
"https://nvd.nist.gov/vuln/detail/CVE-2026-2575",
"https://access.redhat.com/errata/RHSA-2026:76128",
"https://access.redhat.com/errata/RHSA-2026:76129",
"https://access.redhat.com/errata/RHSA-2026:76130",
"https://access.redhat.com/errata/RHSA-2026:76132",
"https://access.redhat.com/errata/RHSA-2026:76134"
],
"provider_metadata": {
"cpes": [
"cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*",
"cpe:2.3:a:keycloak:keycloak:*:*:*:*:*:*:*:*"
],
"severity": "Medium"
}
},
"related_cves": [
{
"value": "CVE-2026-2575",
"evidence": "/aliases"
}
],
"security_relevant": true,
"severity_evidence": "/database_specific/severity"
},
"source_id": "core-osv",
"document_id": 95111,
"published_at": "2026-08-25T11:42:11.943+00:00"
}