SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar install and uninstall endpoints, allowing authenticated administrators to perform path traversal via directory traversal sequences. Attackers with admin access can write arbitrary files to any location via install operations or recursively delete directories via uninstall operations by supplying crafted packageName values.
CVE-2026-77086
CRITICALPre-NVD 9.19.1—Trending — 3 sources updated this week
EchelonGraph scoreHIGH confidence
Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-21. a secondary CVSS source baseline 9.1; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 9.1Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.1
- EG Score
- 9.1(high)
- EG Risk
- 41(Track)EG Risk 41/100SSVC: 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 computedSeverity91% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
Published
August 21, 2026
Last Modified
August 21, 2026
Advisory Details (2)
Auto-updated Aug 21, 2026Patch available. Sources: github.
generic
SiYuan before v3.7.4 Path Traversal via packageName | Advisories | VulnCheck
https://www.vulncheck.com/advisories/siyuan-before-path-traversal-via-packagenamegithub Patch Available
Path Traversal via unvalidated packageName across all 10 Bazaar install/uninstall endpoints, enabling arbitrary-location file write (install) and arbitrary recursive directory deletion (uninstall) · Advisory · siyuan-note/siyuan · GitHub
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-wr4w-7vjm-mmx3Vendor Advisories for CVE-2026-77086(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
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.
- 2026-08-21 23:54 UTCGHSA enrichment
- 2026-08-21 20:03 UTCGHSA enrichment
- 2026-08-21 16:11 UTCEG score recompute
- 2026-08-21 16:11 UTCGHSA enrichment
- 2026-08-21 12:19 UTCEG score recompute
- 2026-08-21 11:55 UTCEG score recompute
- 2026-08-21 11:21 UTCEG score recompute
- 2026-08-21 11:17 UTCEG score recompute
- 2026-08-21 11:14 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(4)
What is CVE-2026-77086?
CVE-2026-77086 is a critical vulnerability published on August 21, 2026. SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar install and uninstall endpoints, allowing authenticated administrators to perform path traversal via directory traversal sequences. Attackers with admin access can write arbitrary files to any location via install operations…
When was CVE-2026-77086 disclosed?
CVE-2026-77086 was first published in the National Vulnerability Database on August 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-77086?
CVE-2026-77086 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-77086?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77086, 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-2026-77086
Is Your Infrastructure Affected by CVE-2026-77086?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.