VulnerabilityPublished 5 Aug 2026

CVE-2026-55998: SUSE Rancher · Observable Response Discrepancy

Affects SUSE RancherSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium · fixed in 2.14.4 : update SUSE Rancher when convenient.

Data as of 3 Nov 2026, 22:58 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.14.4, 2.13.8, 2.12.12 +1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 5 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade SUSE Rancher to 2.14.4, 2.13.8, 2.12.12 or 2.11.16.

Affected software

Product	Affected	Fixed in
SUSERancher	Affected >=2.14.0 <2.14.4	Fixed in 2.14.4
SUSERancher	Affected >=2.13.0 <2.13.8	Fixed in 2.13.8
SUSERancher	Affected >=2.12.0 <2.12.12	Fixed in 2.12.12
SUSERancher	Affected >=2.11.0 <2.11.16	Fixed in 2.11.16
GitHubrancher/rancher`pkg:github/rancher/rancher`Other threats	Affected 2.11.0 – 2.14.0 4 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

CVE-2026-55998 is a medium severity vulnerability in SUSE Rancher versions 2.11.0, 2.12.0, 2.13.0, and 2.14.0. The issue arises from an endpoint that retrieves cluster objects before validating tokens, causing different HTTP responses based on the existence of cluster IDs and their configuration. This discrepancy allows attackers to reliably enumerate valid cluster IDs.

Impact

An attacker can use the observable difference in HTTP response codes to enumerate valid cluster IDs in SUSE Rancher. This information disclosure could aid further targeted attacks. There is no direct impact on integrity or availability, and the confidentiality impact is limited to information disclosure of cluster existence.

Summary

The vulnerability exists in the /v3/import/{token}_{clusterId}.yaml endpoint of SUSE Rancher. The endpoint fetches the cluster object prior to token validation. If a valid cluster ID references a cluster with private registry secrets, a nil pointer dereference in pkg/systemtemplate/private_registry.go causes the endpoint to return an HTTP 502 Bad Gateway error. Conversely, for non-existent cluster IDs, the endpoint returns HTTP 200. This difference in response codes creates an observable response discrepancy, enabling an attacker to enumerate valid cluster IDs. The CVSS 3.1 base score is 5.3 (medium severity), reflecting network attack vector, low complexity, no privileges required, no user interaction, unchanged scope, limited confidentiality impact, and no integrity or availability impact.

CWE-204Observable Response Discrepancy (opens in a new tab)
Base weakness
The product provides different responses to incoming requests in a way that reveals internal state information to an unauthorized actor outside of the intended control sphere.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
Implementation
Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended).
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
ICMP IP Total Length Field Probe (opens in a new tab)
ICMP IP 'ID' Field Error Message Probe (opens in a new tab)
Application Fingerprinting (opens in a new tab)
System Footprinting (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 12 Aug 2026, 15:55 UTC

WeaknessesCWE-204

Technical details

References

Community reviews

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