CVE-2026-29186

CRITICALNVD 9.89.8
EchelonGraph scoreLOW confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.8Exploit: NoneExposed: 0

A fix is available — apply it.

Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbitrary code execution. The @backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml that causes arbitrary Python code execution, completely bypassing TechDocs' security controls. This issue has been patched in version 1.14.3.

CVSS v3
9.8
EG Score
9.8(low)
EPSS
51.6%
KEV
Not listed

Published

March 7, 2026

Last Modified

June 30, 2026

Advisory Details (6)

Auto-updated Jun 30, 2026
Patch available. Sources: github, redhat.
redhat Patch Available
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29186.json
redhat

2445480 – (CVE-2026-29186) CVE-2026-29186 backstage/plugin-techdocs-node: TechDocs Mkdocs configuration key enables arbitrary code execution

https://bugzilla.redhat.com/show_bug.cgi?id=2445480
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-29186
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:9742
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:13826
github Patch Available

TechDocs Mkdocs Configuration Key Enables Arbitrary Code Execution · Advisory · backstage/backstage · GitHub

https://github.com/backstage/backstage/security/advisories/GHSA-928r-fm4v-mvrw

Vendor Advisories for CVE-2026-29186(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhdh/rhdh-hub-rhel9:17779032622026-05-05redhat
redhatrhdh/rhdh-hub-rhel9:17767842862026-04-22redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(3)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 11× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 02:23 UTCEPSS rescore
  4. 2026-07-06 02:23 UTCEPSS rescore
  5. 2026-07-05 02:30 UTCEPSS rescore
  6. 2026-07-04 06:31 UTCEPSS rescore
  7. 2026-07-01 15:06 UTCEPSS rescore
  8. 2026-06-30 23:22 UTCEPSS rescore
  9. 2026-06-30 04:40 UTCEG score recompute
  10. 2026-06-30 04:40 UTCVendor advisory
  11. 2026-06-30 04:31 UTCNVD updatefirst tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-29186?
CVE-2026-29186 is a critical vulnerability published on March 7, 2026. Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbitrary code execution. The @backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the…
When was CVE-2026-29186 disclosed?
CVE-2026-29186 was first published in the National Vulnerability Database on March 7, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-29186 actively exploited?
CVE-2026-29186 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 51.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-29186?
CVE-2026-29186 has a CVSS v3 base score of 9.8 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-29186?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-29186, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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