Security readout for executives and security teams
Plain-English summary
A remote user may submit Tempo searches with very large result limits, causing excessive memory allocation and potentially taking the tracing service offline. The documented impact is availability loss, not data theft or modification. Business impact depends on whether affected query interfaces are reachable and whether deployment isolation or automatic recovery limits disruption.
Executive priority
Treat as a high-priority availability risk for externally reachable or shared observability platforms. Apply the documented result limit promptly and verify it is effective. Accelerate action where tracing outages would impair incident response, production diagnosis, or service-level commitments. There is no supplied evidence of active exploitation, so emergency incident status is not currently justified.
Technical view
CVE-2026-21728 is a CWE-400/CWE-770 resource-consumption flaw in Grafana Tempo and Enterprise Traces. Large query limits can trigger unbounded memory allocation. Its CVSS 3.1 score is 7.5: network-accessible, low complexity, no privileges or interaction required, with high availability impact and no stated confidentiality or integrity impact.
Likely exposure
The bundle specifically lists Tempo 1.3.0, 2.9.0, and 2.10.0, plus Enterprise Traces 1.0.0. It marks other versions unaffected by default, but does not explain whether listed versions represent exact releases or range boundaries. Prioritize deployments whose query interfaces are reachable by untrusted users and confirm version interpretation with Grafana.
Exploitation context
The CVE is not listed in KEV, and the supplied sources provide no evidence of active exploitation or a public exploit. The CVSS vector nevertheless indicates remote, unauthenticated, low-complexity triggering. Actual exploitability depends on query-interface reachability and deployment controls, which the bundle does not describe.
Researcher notes
The core condition is insufficient allocation control when processing large query limits. Relevant classifications are CWE-400 and CWE-770. Deployment strategy materially changes impact. The bundle does not identify the vulnerable component path, exact affected-version range semantics, fixed versions, patch commits, observed attacks, or authentication behavior beyond the CVSS vector.
Mitigation direction
- Set the search configuration's max_result_limit to 262144 or lower, following Grafana's documented example.
- If configuration cannot be changed promptly, use automatic service restarts as the documented availability workaround.
- Review Grafana and applicable Red Hat advisories for fixed releases or package-specific remediation guidance.
Validation and detection
- Inventory Tempo and Enterprise Traces deployments and compare versions against those specifically listed in the CVE bundle.
- Verify the effective search configuration enforces max_result_limit at 262144 or lower.
- Determine whether untrusted or unauthenticated users can reach affected query interfaces.
- Under approved load testing, confirm oversized-limit queries remain bounded without unsafe memory growth.
- If relying on restarts, verify automation restores service reliably after memory-related failure.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-770: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-21728 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6GRAFANACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat-SADPVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-04-24T09:00:58.144Z: Reported to Red Hat.
- 2026-04-24T08:00:47.074Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://grafana.com/security/security-advisories/cve-2026-21728CVE reference, GRAFANA · vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-21728CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2461395CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-21728.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:22423CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:22347CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:23345CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:24503CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:21769CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Allocation of Resources Without Limits or Throttling
Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.