Viewer role can create, modify and delete Loki alerting rules (CVE-2026-9703)
Published Last modified Sources: OSV, CVE.org, BSI
What is affected, what to do
Grafana's data source proxy did not apply role-based access control to write requests forwarded to Loki data sources. A user holding only the Viewer role on an affected Grafana instance could send POST, PUT and DELETE requests through the proxy to the Loki rules API (/loki/api/v1/rules), allowing them to create, modify and delete Loki alerting rules.
Update Grafana to version 12.3.9.
- Affected
- Grafana Enterprise
lte 8.0.0..11.5.10 - Grafana Enterprise
lte 11.6.0..11.6.16 - Grafana Enterprise
lte 12.0.0..12.1.10 - Grafana Enterprise
lte 12.2.0..12.2.10 - Grafana Enterprise
lte 12.3.0..12.3.8 - Grafana Enterprise
lte 12.4.0..12.4.5 - Grafana Enterprise
lte 13.0.0..13.0.3 - Grafana OSS
lte 12.3.0..12.3.8 - Grafana OSS
lte 12.4.0..12.4.5 - Grafana OSS
lte 8.0.0..12.3.0 - Grafana OSS
lte 13.0.0..13.0.3
- Grafana Enterprise
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Metrics
7.1
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: Vendor (CNA), CVSS v3
7.1
CVSS v3
Severity High on the scale from 0 to 10.
Source: OSV, CVE.org, BSI
0.2 %
EPSS score
Low — model estimates < 1% exploitation likelihood.
Source: FIRST EPSS, percentile 9.1
Show all metrics
- Severity
- High
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 66.17 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 7.1 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 7.1
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 0.2 %
- Low — model estimates < 1% exploitation likelihood.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 9.1
- Low — this CVE sits in the lower 10% of all CVEs scored today.
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
- CISA assessment (SSVC)
- Exploitation: none known · not automatable · Technical impact: partial
- Source: CISA Vulnrichment, as of 16 October 2026
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-284
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
Grafana's data source proxy did not apply role-based access control to write requests forwarded to Loki data sources. A user holding only the Viewer role on an affected Grafana instance could send POST, PUT and DELETE requests through the proxy to the Loki rules API (/loki/api/v1/rules), allowing them to create, modify and delete Loki alerting rules. Because those rules are stored by Loki rather than by Grafana, the change took effect for every user of that Loki data source, not only for the Viewer who made the request. Exploitation requires an authenticated Viewer account on the Grafana instance and a configured Loki data source; no other privileges are needed. Both Grafana OSS and Grafana Enterprise are affected. The defect is in Grafana's data source proxy; Loki itself is not vulnerable and does not need to be patched.
Source: OSV (Open Source Vulnerabilities), cvelistv5, NVD (NIST), BSI CSAF, BSI WID Portal
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Grafana | Grafana Enterprise |
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| Grafana | Grafana OSS |
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| Grafana | Grafana |
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Distribution and container packages (3)
Downstream packages (e.g. Bitnami, Debian, Ubuntu, Red Hat). Versions refer to the distribution, not the vendor.
| Affected versions | Fixed in | ||
|---|---|---|---|
| bitnami | grafana |
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Vendors and products
Weakness classes (CWE)
CWE-284Improper Access Control
Pillar
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
Entry at MITRE CWE-284
References & sources
- grafana.comsecurity/security-advisories/cve-2026-9703Vendor advisory, web
- NVD (NIST)vuln/detail/CVE-2026-9703web
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
Record modifiedCISA ADP
CISA assessment (SSVC): exploitation: none known, automatable: no
Show the original change
Individual changes of this event as published by NVD Type Action Before After SSVC assessment added —{"id":"CVE-2026-9703","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T18:52:22.846867Z"}Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Receivedgrafana.com
CVSS V3.1: AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
Weakness type: CWE-284
Description added or changed
Show 5 original changes
Individual changes of this event as published by NVD Type Action Before After Description added —Grafana's data source proxy did not apply role-based access control to write requests forwarded to Loki data sources. A user holding only the Viewer role on an affected Grafana instance could send POST, PUT and DELETE requests through the proxy to the Loki rules API (/loki/api/v1/rules), allowing them to create, modify and delete Loki alerting rules. Because those rules are stored by Loki rather than by Grafana, the change took effect for every user of that Loki data source, not only for the Viewer who made the request. Exploitation requires an authenticated Viewer account on the Grafana instance and a configured Loki data source; no other privileges are needed. Both Grafana OSS and Grafana Enterprise are affected. The defect is in Grafana's data source proxy; Loki itself is not vulnerable and does not need to be patched.CVSS added —AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:LWeakness type (CWE) added —CWE-284Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/9xxx/CVE-2026-9703.json">CVE-2026-9703</a>Reference added —https://grafana.com/security/security-advisories/cve-2026-9703Source identifier: security@grafana.com
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-9703"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-9703.svg?lang=en" alt="CVE-2026-9703 – NEOSEC Intel" height="20"></a>