CVE-2026-55996
- Source
- https://cve.org/CVERecord?id=CVE-2026-55996
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55996.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-55996
- Aliases
-
- GHSA-9jxv-832x-45q9
- Published
- 2026-08-05T07:46:43.831Z
- Modified
- 2026-08-12T03:51:20.204203535Z
- Severity
-
- 4.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
- Summary
- Unauthenticated Denial-of-Service via TLS SAN Stuffing in Rancher and cattle-cluster-agent
- Details
-
A denial-of-service vulnerability was identified in multiple TLS listeners in Rancher. Both the cattle-cluster-agent component running in downstream clusters and the Rancher server itself use the dynamiclistener library to serve TLS traffic. Without an effective CN filter configured, dynamiclistener automatically appended to each serving certificate any hostname presented via Server Name Indication (SNI) in incoming TLS requests.
An unauthenticated attacker with network access within the affected cluster could send a large number of TLS requests with distinct hostnames, causing the serving certificate to accumulate an unbounded number of Subject Alternative Names (SANs). Eventually, the certificate grows large enough that TLS handshakes fail with an excessive message size error, causing a denial of service on the affected listeners.
- Database specific
{ "cna_assigner": "suse", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55996.json" }- References
Affected packages
Git / github.com/rancher/rancher
Affected ranges
- Type
- GIT
- Repo
- https://github.com/rancher/rancher
- Events
-
IntroducedFixedIntroducedFixedIntroducedFixedIntroducedFixed
- Database specific
-
Show details
{ "extracted_events": [ { "introduced": "2.11.0" }, { "fixed": "2.11.16" }, { "introduced": "2.12.0" }, { "fixed": "2.12.12" }, { "introduced": "2.13.0" }, { "fixed": "2.13.8" }, { "introduced": "2.14.0" }, { "fixed": "2.14.4" } ], "source": "AFFECTED_FIELD" }
Affected versions
v2.*
v2.11.0
v2.11.1
v2.11.1-alpha1
v2.11.1-alpha2
v2.11.1-alpha3
v2.11.1-rc1
v2.11.1-rc2
v2.11.10
v2.11.10-alpha1
v2.11.10-rc1
v2.11.10-rc2
v2.11.11
v2.11.11-alpha1
v2.11.11-alpha2
v2.11.11-rc1
v2.11.12
v2.11.12-alpha1
v2.11.12-rc1
v2.11.13
v2.11.13-alpha1
v2.11.13-alpha2
v2.11.13-alpha3
v2.11.13-alpha4
v2.11.13-alpha5
v2.11.13-alpha6
v2.11.13-rc1
v2.11.14
v2.11.14-alpha1
v2.11.14-rc1
v2.11.15
v2.11.15-alpha1
v2.11.15-alpha2
v2.11.15-alpha3
v2.11.15-alpha4
v2.11.15-rc1
v2.11.16-alpha1
v2.11.16-alpha2
v2.11.16-alpha3
v2.11.16-alpha4
v2.11.16-alpha5
v2.11.16-alpha6
v2.11.16-rc1
v2.11.2
v2.11.2-alpha1
v2.11.2-alpha2
v2.11.2-alpha3
v2.11.2-alpha4
v2.11.2-rc1
v2.11.2-rc2
v2.11.3
v2.11.3-alpha1
v2.11.3-alpha2
v2.11.3-alpha3
v2.11.3-rc1
v2.11.4
v2.11.4-alpha1
v2.11.4-alpha2
v2.11.4-alpha3
v2.11.4-alpha4
v2.11.4-alpha5
v2.11.4-rc1
v2.11.5
v2.11.5-alpha1
v2.11.5-alpha2
v2.11.5-alpha3
v2.11.5-rc1
v2.11.6
v2.11.6-alpha1
v2.11.6-alpha2
v2.11.6-alpha3
v2.11.6-alpha4
v2.11.6-rc1
v2.11.7
v2.11.7-alpha1
v2.11.7-alpha2
v2.11.7-rc1
v2.11.7-rc2
v2.11.8
v2.11.8-alpha1
v2.11.8-alpha2
v2.11.8-alpha3
v2.11.8-alpha4
v2.11.8-alpha5
v2.11.8-rc1
v2.11.9
v2.11.9-alpha1
v2.11.9-alpha2
v2.11.9-rc1
v2.12.0
v2.12.1
v2.12.1-alpha1
v2.12.1-alpha2
v2.12.1-alpha3
v2.12.1-alpha4
v2.12.1-rc1
v2.12.10
v2.12.10-alpha1
v2.12.10-alpha2
v2.12.10-alpha3
v2.12.10-alpha4
v2.12.10-alpha5
v2.12.10-rc1
v2.12.11
v2.12.11-alpha1
v2.12.11-alpha2
v2.12.11-alpha3
v2.12.11-alpha4
v2.12.11-alpha5
v2.12.11-rc1
v2.12.12-alpha1
v2.12.12-alpha2
v2.12.12-alpha3
v2.12.12-alpha4
v2.12.12-alpha5
v2.12.12-alpha6
v2.12.12-alpha7
v2.12.12-alpha8
v2.12.12-alpha9
v2.12.12-rc1
v2.12.2
v2.12.2-alpha1
v2.12.2-alpha2
v2.12.2-alpha3
v2.12.2-alpha4
v2.12.2-alpha5
v2.12.2-rc1
v2.12.2-rc2
v2.12.3
v2.12.3-alpha1
v2.12.3-alpha2
v2.12.3-rc1
v2.12.4
v2.12.4-alpha1
v2.12.4-alpha2
v2.12.4-alpha3
v2.12.4-alpha4
v2.12.4-alpha5
v2.12.4-alpha6
v2.12.4-hotfix-a3c0.1
v2.12.4-rc1
v2.12.5
v2.12.5-alpha1
v2.12.5-alpha2
v2.12.5-rc1
v2.12.6
v2.12.6-alpha1
v2.12.6-alpha2
v2.12.6-rc1
v2.12.6-rc2
v2.12.7
v2.12.7-alpha1
v2.12.7-alpha2
v2.12.7-alpha3
v2.12.7-rc1
v2.12.8
v2.12.8-alpha1
v2.12.8-alpha2
v2.12.8-rc1
v2.12.9
v2.12.9-alpha1
v2.12.9-alpha2
v2.12.9-alpha3
v2.12.9-alpha4
v2.12.9-alpha5
v2.12.9-alpha6
v2.12.9-alpha7
v2.12.9-rc1
v2.13.0
v2.13.0-rc4
v2.13.1
v2.13.1-alpha1
v2.13.1-alpha2
v2.13.1-alpha3
v2.13.1-alpha4
v2.13.1-alpha5
v2.13.1-alpha6
v2.13.1-alpha7
v2.13.1-rc1
v2.13.2
v2.13.2-alpha1
v2.13.2-alpha2
v2.13.2-alpha3
v2.13.2-alpha4
v2.13.2-alpha5
v2.13.2-alpha6
v2.13.2-alpha7
v2.13.2-rc1
v2.13.2-rc2
v2.13.3
v2.13.3-alpha1
v2.13.3-alpha2
v2.13.3-alpha3
v2.13.3-alpha4
v2.13.3-alpha5
v2.13.3-alpha6
v2.13.3-rc1
v2.13.3-rc2
v2.13.3-rc3
v2.13.4
v2.13.4-alpha1
v2.13.4-alpha2
v2.13.4-alpha3
v2.13.4-alpha4
v2.13.4-alpha5
v2.13.4-rc1
v2.13.5
v2.13.5-alpha1
v2.13.5-alpha2
v2.13.5-alpha3
v2.13.5-alpha4
v2.13.5-alpha5
v2.13.5-alpha6
v2.13.5-alpha7
v2.13.5-rc1
v2.13.6
v2.13.6-alpha1
v2.13.6-alpha2
v2.13.6-alpha3
v2.13.6-alpha4
v2.13.6-alpha5
v2.13.6-alpha6
v2.13.6-rc1
v2.13.7
v2.13.7-alpha1
v2.13.7-alpha2
v2.13.7-alpha3
v2.13.7-alpha4
v2.13.7-alpha5
v2.13.7-alpha6
v2.13.7-alpha7
v2.13.7-rc1
v2.13.8-alpha1
v2.13.8-alpha2
v2.13.8-alpha3
v2.13.8-alpha4
v2.13.8-alpha5
v2.13.8-alpha6
v2.13.8-alpha7
v2.13.8-alpha8
v2.13.8-rc1
v2.14.0
v2.14.1
v2.14.1-alpha1
v2.14.1-alpha10
v2.14.1-alpha11
v2.14.1-alpha12
v2.14.1-alpha13
v2.14.1-alpha14
v2.14.1-alpha2
v2.14.1-alpha3
v2.14.1-alpha4
v2.14.1-alpha5
v2.14.1-alpha6
v2.14.1-alpha7
v2.14.1-alpha8
v2.14.1-alpha9
v2.14.1-rc1
v2.14.1-rc2
v2.14.2
v2.14.2-alpha1
v2.14.2-alpha2
v2.14.2-alpha3
v2.14.2-alpha4
v2.14.2-alpha5
v2.14.2-alpha6
v2.14.2-alpha7
v2.14.2-alpha8
v2.14.2-rc1
v2.14.3
v2.14.3-alpha1
v2.14.3-alpha2
v2.14.3-alpha3
v2.14.3-alpha4
v2.14.3-alpha5
v2.14.3-alpha6
v2.14.3-rc1
v2.14.4-alpha1
v2.14.4-alpha2
v2.14.4-alpha3
v2.14.4-alpha4
v2.14.4-alpha5
v2.14.4-alpha6
v2.14.4-alpha7
v2.14.4-rc1