Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.27% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-88808High confidence
Fleet agent copies downstream resources with cluster-admin privileges, allowing cross-namespace writes on downstream clusters
SUSE · Rancher
Official source article: GitHub GHSA-Q9V4-358V-R8Q5 ↗. Check the applicable product and release in the original source.
8.8HighCVSS 3.1
Within 7 days
Fix not verifiedHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs SUSE Rancher and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Fix not verified01
What, why and how
A vulnerability has been identified within Rancher Manager where the Fleet agent wrote resources to downstream clusters using its own cluster-admin credentials instead of the ServiceAccount pinned to the deployment. It affects multi-tenancy environments where different tenants share the same downstream clusters, for example different privileged or untrusted teams inside the same organization. This could lead to overwritten configuration files. This issue affected SUSE Rancher Fleet 0.16 before 0.16.2, 0.15 before 0.15.7, and 0.14 before 0.14.11.
What
A vulnerability has been identified within Rancher Manager where the Fleet agent wrote resources to downstream clusters using its own cluster-admin credentials instead of the ServiceAccount pinned to the deployment. It affects multi-tenancy environments where different tenants share the same downstream clusters, for example different privileged or untrusted teams inside the same organization. This could lead to overwritten configuration files. This issue affected SUSE Rancher Fleet 0.16 before 0.16.2, 0.15 before 0.15.7, and 0.14 before 0.14.11.
Why
The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
A vulnerability has been identified within Rancher Manager where the Fleet agent wrote resources to downstream clusters using its own cluster-admin credentials instead of the ServiceAccount pinned to the deployment. It affects multi-tenancy environments where different tenants share the same downstream clusters, for example different privileged or untrusted teams inside the same organization. This could lead to overwritten configuration files. This issue affected SUSE Rancher Fleet 0.16 before 0.16.2, 0.15 before 0.15.7, and 0.14 before 0.14.11.
Why
The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Execution with Unnecessary Privileges → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-250 ↗
CWE-250: Execution with Unnecessary Privileges. The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix not verified
- Affected
- Rancher: 0.16.0 < 0.16.2, 0.15.0 < 0.15.7, 0.14.0 < 0.14.11
- Fixed
- No fixed version is explicitly recorded in the structured CVE data.
- Action
- No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 28 Sept 2026 · Last source change 29 Sept 2026, 03:55 UTC · CWE-250 · Execution with Unnecessary Privileges
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-09-29
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-88335
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-88335 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-88335"}
- Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: github.com/GHSA-q9v4-358v-r8q5.meissner@suse.de ↗
- Before
- no authoritative guidance recorded
- After
- vendor advisory: github.com/GHSA-q9v4-358v-r8q5
- Vendor guidanceAuthoritative vendor guidance changed: removed vendor advisory: github.com/GHSA-q9v4-358v-r8q5.CNA ↗
- Before
- vendor advisory: github.com/GHSA-q9v4-358v-r8q5
- After
- no authoritative guidance recorded
- Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: github.com/GHSA-q9v4-358v-r8q5; removed remediation: wid.cert-bund.de/securityadvisory?name=WID-SEC-2026-3546.github.com ↗
- Before
- remediation: wid.cert-bund.de/securityadvisory?name=WID-SEC-2026-3546
- After
- vendor advisory: github.com/GHSA-q9v4-358v-r8q5
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- Open Source Fleet <0.16.2; Open Source Fleet <0.16.1; Open Source Fleet <0.15.6; Open Source Fleet <0.14.10; Open Source Fleet <0.15.7 · Fixed: No fixed version is explicitly recorded in this authority advisory.
- After
- Rancher: 0.16.0 < 0.16.2, 0.15.0 < 0.15.7, 0.14.0 < 0.14.11 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- SeveritySeverity changed from Unknown to High.CNA ↗
- Before
- Unknown
- After
- High
- CVSS scoreCVSS score changed from not recorded to 8.8 (CVSS 3.1 · CNA · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).CNA ↗
- Before
- not recorded
- After
- 8.8 (CVSS 3.1 · CNA · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
- Catalogue recordCVE added to the BlackTree catalogue.Official national cybersecurity authority ↗
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.