Backstage is an open framework for building developer portals. Prior to 1.14.6 and from 1.15.0 until 1.15.4, the @backstage/plugin-techdocs-node package insufficiently validates mkdocs.yml supplied by an authenticated user who can register or modify a TechDocs source. Unsafe Python YAML tags, markdown_extensions names and configuration, theme options, and extra_templates values can reach the documentation generator and cause unintended code execution. The resulting impact is limited to the files, credentials, network access, and other resources available to the TechDocs backend or build container. This issue is fixed in versions 1.14.6 and 1.15.4.
CVE-2026-88064
HIGHPre-NVD 8.88.8—Trending — 3 sources updated this week
EchelonGraph scoreMEDIUM confidence
This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 51% of all CVEs by exploit prediction. 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: epss, secondary
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.8Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.8
- EG Score
- 8.8(medium)
- EG Risk
- 40(Track)EG Risk 40/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity88% × 45%Exploitation1% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 49%
- KEV
- Not listed
Published
September 16, 2026
Last Modified
September 16, 2026
Advisory Details (8)
Auto-updated Sep 16, 2026Patch available. Sources: github_commit, github_release, github.
github_release Patch Available
v1.54.6
Patch available: backstage/backstage v1.54.6
https://github.com/backstage/backstage/releases/tag/v1.54.6github_release Patch Available
v1.50.5
Patch available: backstage/backstage v1.50.5
https://github.com/backstage/backstage/releases/tag/v1.50.5github_commit Patch Available
commit a900a9953c8f (backstage/backstage)
Patch available: backstage/backstage v1.50.5 (contains commit a900a9953c8f)
https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9dgithub_commit Patch Available
commit a7d995f11a5d (backstage/backstage)
Patch available: backstage/backstage v1.54.6 (contains commit a7d995f11a5d)
https://github.com/backstage/backstage/commit/a7d995f11a5d27f0efbdbe8bb6c21b06988c79c9github_commit Patch Available
commit 25125ee727a3 (backstage/backstage)
Patch available: backstage/backstage v1.54.6 (contains commit 25125ee727a3)
https://github.com/backstage/backstage/commit/25125ee727a3de3418a8fa6a9e458cd5b73ecf26github_commit Patch Available
commit 02cd7cdbb18b (backstage/backstage)
Patch available: backstage/backstage v1.54.6 (contains commit 02cd7cdbb18b)
https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbbgithub_commit Patch Available
commit 017ace52d9b3 (backstage/backstage)
Patch available: backstage/backstage v1.54.6 (contains commit 017ace52d9b3)
https://github.com/backstage/backstage/commit/017ace52d9b327ededc6704cf17799c875ae0f29github Patch Available
Improper input validation in TechDocs MkDocs configuration · Advisory · backstage/backstage · GitHub
https://github.com/backstage/backstage/security/advisories/GHSA-292q-8mf5-h6g3Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 9× 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.
- 2026-09-18 21:14 UTCEG score recompute
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-18 08:00 UTCEG score recompute
- 2026-09-17 19:32 UTCEPSS rescore
- 2026-09-16 16:34 UTCEG score recompute
- 2026-09-16 15:55 UTCEG score recompute
- 2026-09-16 15:20 UTCEG score recompute
- 2026-09-16 14:26 UTCEG score recompute
- 2026-09-16 14:25 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-20
- CVE-2005-0050EG 10.0EPSS p99HIGH
- CVE-2004-1019EG 10.0EPSS p94HIGH
- CVE-2004-0840EG 10.0EPSS p98HIGH
- CVE-2003-1425EG 10.0EPSS p96HIGH
- CVE-2003-1487EG 10.0EPSS p95HIGH
- CVE-2002-1874EG 10.0HIGH
- CVE-2002-2236EG 10.0EPSS p92HIGH
- CVE-2002-2365EG 10.0HIGH
- CVE-2002-1358EG 10.0EPSS p93HIGH
- CVE-2002-1359EG 10.0EPSS p100HIGH
Frequently asked(5)
What is CVE-2026-88064?
CVE-2026-88064 is a high vulnerability published on September 16, 2026. Backstage is an open framework for building developer portals. Prior to 1.14.6 and from 1.15.0 until 1.15.4, the @backstage/plugin-techdocs-node package insufficiently validates mkdocs.yml supplied by an authenticated user who can register or modify a TechDocs source. Unsafe Python YAML tags,…
When was CVE-2026-88064 disclosed?
CVE-2026-88064 was first published in the National Vulnerability Database on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-88064 actively exploited?
CVE-2026-88064 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 51.1% of all scored CVEs.
What is the CVSS score of CVE-2026-88064?
CVE-2026-88064 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-88064?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-88064, 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
Explore the affected products and dependency analysis for CVE-2026-88064
Is Your Infrastructure Affected by CVE-2026-88064?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.