MediumFix available
xen — security advisory
Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES command within a transaction due to an assert() triggering. In case xenstored was built with NDEBUG #defined nothing bad will happen, as assert() is doing nothing in this case. Note that the default is not to define NDEBUG for xenstored builds even in release builds of Xen.
- Products
- xen
- Affected versions
- 4.17.1+2-gb773c48e36-1, 4.17.2+55-g0b56bed864-1, 4.17.2+76-ge1f9cb16e2-1, 4.17.2+76-ge1f9cb16e2-1~deb12u1, 4.17.2-1, 4.17.3+10-g091466ba55-1, 4.17.3+10-g091466ba55-1.1, 4.17.3+10-g091466ba55-1.1~exp1, 4.17.3+10-g091466ba55-1.1~exp2, 4.17.3+10-g091466ba55-1~deb12u1, 4.17.3+36-g54dacb5c02-1, 4.17.5+23-ga4e5191dc0-1, 4.17.5+23-ga4e5191dc0-1+deb12u1, 4.17.5+72-g01140da4e8-1, 4.20.0+68-g35cb38b222-1, 4.20.2+37-g61ff35323e-0+deb13u1, 4.20.2+37-g61ff35323e-1, 4.20.2+7-g1badcf5035-0+deb13u1, 4.20.2+7-g1badcf5035-1, 4.20.2+7-g1badcf5035-2
- Fixed versions
- 4.17.7-0+deb12u1, 4.20.3+127-gc42374a105-0+deb13u1, 4.20.3+127-gc42374a105-1
- CVEs
- CVE-2026-23557
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 16:39 UTC · Revision 1
Source evidence
Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES command within a transaction due to an assert() triggering. In case xenstored was built with NDEBUG #defined nothing bad will happen, as assert() is doing nothing in this case. Note that the default is not to define NDEBUG for xenstored builds even in release builds of Xen.
osv:DEBIAN-CVE-2026-23557
xen
Fixed versions: 4.17.7-0+deb12u1
xen
Fixed versions: 4.20.3+127-gc42374a105-0+deb13u1
xen
Fixed versions: 4.20.3+127-gc42374a105-1
Complete source record
{
"id": "335465f10fb5650b7b04a566871a902cd3b4862c949d098949bd4aa9eb162bd1",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-23557",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-23557",
"summary": "Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES command within a transaction due to an assert() triggering. In case xenstored was built with NDEBUG #defined nothing bad will happen, as assert() is doing nothing in this case. Note that the default is not to define NDEBUG for xenstored builds even in release builds of Xen.",
"evidence": "osv:DEBIAN-CVE-2026-23557",
"products": [
{
"name": {
"value": "xen",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.17.7-0+deb12u1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "4.17.1+2-gb773c48e36-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.2+55-g0b56bed864-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.2+76-ge1f9cb16e2-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.2+76-ge1f9cb16e2-1~deb12u1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.3+10-g091466ba55-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.3+10-g091466ba55-1.1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.3+10-g091466ba55-1.1~exp1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.3+10-g091466ba55-1.1~exp2",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.3+10-g091466ba55-1~deb12u1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.3+36-g54dacb5c02-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.5+23-ga4e5191dc0-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.5+23-ga4e5191dc0-1+deb12u1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.5+72-g01140da4e8-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "xen",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.20.3+127-gc42374a105-0+deb13u1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "4.20.0+68-g35cb38b222-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.20.2+37-g61ff35323e-0+deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "4.20.2+37-g61ff35323e-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.20.2+7-g1badcf5035-0+deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "4.20.2+7-g1badcf5035-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.20.2+7-g1badcf5035-2",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "xen",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.20.3+127-gc42374a105-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "4.20.0+68-g35cb38b222-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.20.2+37-g61ff35323e-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.20.2+7-g1badcf5035-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.20.2+7-g1badcf5035-2",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2026-23557",
"aliases": [
"DEBIAN-CVE-2026-23557"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.17.7-0+deb12u1"
}
]
}
],
"package": {
"name": "xen",
"purl": "pkg:deb/debian/xen?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"4.17.1+2-gb773c48e36-1",
"4.17.2+55-g0b56bed864-1",
"4.17.2+76-ge1f9cb16e2-1",
"4.17.2+76-ge1f9cb16e2-1~deb12u1",
"4.17.2-1",
"4.17.3+10-g091466ba55-1",
"4.17.3+10-g091466ba55-1.1",
"4.17.3+10-g091466ba55-1.1~exp1",
"4.17.3+10-g091466ba55-1.1~exp2",
"4.17.3+10-g091466ba55-1~deb12u1",
"4.17.3+36-g54dacb5c02-1",
"4.17.5+23-ga4e5191dc0-1",
"4.17.5+23-ga4e5191dc0-1+deb12u1",
"4.17.5+72-g01140da4e8-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-23557.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.20.3+127-gc42374a105-0+deb13u1"
}
]
}
],
"package": {
"name": "xen",
"purl": "pkg:deb/debian/xen?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"4.20.0+68-g35cb38b222-1",
"4.20.2+37-g61ff35323e-0+deb13u1",
"4.20.2+37-g61ff35323e-1",
"4.20.2+7-g1badcf5035-0+deb13u1",
"4.20.2+7-g1badcf5035-1",
"4.20.2+7-g1badcf5035-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-23557.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.20.3+127-gc42374a105-1"
}
]
}
],
"package": {
"name": "xen",
"purl": "pkg:deb/debian/xen?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"4.20.0+68-g35cb38b222-1",
"4.20.2+37-g61ff35323e-1",
"4.20.2+7-g1badcf5035-1",
"4.20.2+7-g1badcf5035-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-23557.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
}
],
"modified": "2026-10-15T09:47:35.636210013Z",
"provider": "osv",
"upstream": [
"CVE-2026-23557"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-23557"
]
},
"related_cves": [
{
"value": "CVE-2026-23557",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 327838,
"published_at": "2026-05-19T14:16:38.817+00:00"
}