DEBIAN-CVE-2026-27889
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.2.0 and prior to versions 2.11.14 and 2.12.5, a missing sanity check on a WebSockets frame could trigger a server panic in the nats-server. This happens before authentication, and so is exposed to anyone who can connect to the websockets port. Versions 2.11.14 and 2.12.5 contains a fix. A workaround is available. The vulnerability only affects deployments which use WebSockets and which expose the network port to untrusted end-points. If one is able to do so, a defense in depth of restricting either of these will mitigate the attack.
DEBIAN-CVE-2026-27889
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-27889
nats-server
Source reference: /affected/0/package/name
- Affected versions
- 2.10.1-1
Source reference:
/affected/0/versions2.10.16-1Source reference:
/affected/0/versions2.10.18-1Source reference:
/affected/0/versions2.10.24-1Source reference:
/affected/0/versions2.10.27-1Source reference:
/affected/0/versions2.10.3-1Source reference:
/affected/0/versions2.10.4-1Source reference:
/affected/0/versions2.10.7-1Source reference:
/affected/0/versions2.12.4-1Source reference:
/affected/0/versions2.12.6-1Source reference:
/affected/0/versions2.14.1-1Source reference:
/affected/0/versions2.14.3-1Source reference:
/affected/0/versions2.14.6-1Source reference:
/affected/0/versions2.9.10-1Source reference:
/affected/0/versions2.9.19-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
nats-server
Source reference: /affected/1/package/name
- Affected versions
- 2.10.27-1
Source reference:
/affected/1/versions2.12.4-1Source reference:
/affected/1/versions2.12.6-1Source reference:
/affected/1/versions2.14.1-1Source reference:
/affected/1/versions2.14.3-1Source reference:
/affected/1/versions2.14.6-1Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
nats-server
Source reference: /affected/2/package/name
- Affected versions
- 2.10.27-1
Source reference:
/affected/2/versions2.12.4-1Source reference:
/affected/2/versions - Fixed versions
- 2.12.6-1
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "nats-server",
"purl": "pkg:deb/debian/nats-server?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"2.10.1-1",
"2.10.16-1",
"2.10.18-1",
"2.10.24-1",
"2.10.27-1",
"2.10.3-1",
"2.10.4-1",
"2.10.7-1",
"2.12.4-1",
"2.12.6-1",
"2.14.1-1",
"2.14.3-1",
"2.14.6-1",
"2.9.10-1",
"2.9.19-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27889.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "nats-server",
"purl": "pkg:deb/debian/nats-server?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"2.10.27-1",
"2.12.4-1",
"2.12.6-1",
"2.14.1-1",
"2.14.3-1",
"2.14.6-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27889.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.12.6-1"
}
]
}
],
"package": {
"name": "nats-server",
"purl": "pkg:deb/debian/nats-server?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"2.10.27-1",
"2.12.4-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27889.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #56606 · Revision 1
- Added to Heist Feed
- Publisher date