CVE-2026-72809

HIGHPre-NVD 8.08.0—
EchelonGraph scoreMEDIUM confidence

Score 8.0 from GitHub Security Advisory (severity: HIGH) published 2026-08-12. a secondary CVSS source baseline 8.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
8.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.0Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

SiYuan versions <= v3.7.2 (patched in v3.7.4) contain an authentication bypass vulnerability in the kernel's CheckAuth function, which grants the administrator role (RoleAdministrator) to any request whose RemoteAddr is loopback (127.0.0.1) for a specific set of endpoints (including /api/system/exit, getNetwork, getWorkspaceInfo, /assets/*, and /export/*). These localhost bypasses sit outside the access auth code gate, so they apply even when an access auth code is configured. Because the fixed-port reverse proxy forwards requests to the kernel over loopback without injecting an authentication token and does not configure trusted proxies, a request forwarded through this proxy reaches the kernel with RemoteAddr = 127.0.0.1. If the fixed-port proxy is bound to a network interface, this could allow a remote unauthenticated attacker to obtain admin access on the affected endpoints; however, per the advisory this remote forwarding behavior was established only by code inspection and was not reproduced end-to-end.

CVSS v3
8.0
EG Score
8.0(medium)
EG Risk
52(Track)
EG Risk 52/100SSVC: 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 computed
Severity80% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
11%
KEV
Not listed

Published

August 12, 2026

Last Modified

August 26, 2026

Advisory Details (2)

Auto-updated Aug 12, 2026
No patch confirmed yet.
generic

SiYuan before v3.7.4 Authentication Bypass via Localhost Trust | Advisories | VulnCheck

https://www.vulncheck.com/advisories/siyuan-before-authentication-bypass-via-localhost-trust
github Patch Available🟡 PoC Available

Localhost-trust admin bypass on auth-code-gated endpoints, with potential remote reachability via the fixed-port proxy (needs maintainer confirmation) · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-3mp7-4rh5-jrv9

Vendor Advisories for CVE-2026-72809(1)

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

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/siyuan-note/siyuan/kernel—0.0.0-20260723031701-9c16e9851f0b—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 72× 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.

Showing the most recent 100 of 111 total refreshes for this CVE.

  1. 2026-09-19 03:59 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 02:29 UTCEG score recompute
  4. 2026-09-17 00:18 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-15 15:22 UTCEG score recompute
  8. 2026-09-15 03:12 UTCEPSS rescore
  9. 2026-09-14 00:35 UTCEG score recompute
  10. 2026-09-12 23:06 UTCEG score recompute
  11. 2026-09-12 15:02 UTCEPSS rescore
  12. 2026-09-12 09:47 UTCEG score recompute
  13. 2026-09-11 21:02 UTCEG score recompute
  14. 2026-09-11 14:53 UTCEPSS rescore
  15. 2026-09-10 19:32 UTCEG score recompute
  16. 2026-09-10 09:35 UTCEPSS rescore
  17. 2026-09-09 05:12 UTCEG score recompute
  18. 2026-09-08 22:01 UTCEPSS rescore
  19. 2026-09-07 19:25 UTCEG score recompute
  20. 2026-09-06 17:34 UTCEG score recompute
  21. 2026-09-06 13:48 UTCEPSS rescore
  22. 2026-09-05 16:04 UTCEG score recompute
  23. 2026-09-04 14:15 UTCEG score recompute
  24. 2026-09-04 05:07 UTCEPSS rescore
  25. 2026-09-03 12:43 UTCGHSA enrichment
Show 75 more
  1. 2026-09-02 23:27 UTCEG score recompute
  2. 2026-09-02 23:27 UTCGHSA enrichment
  3. 2026-09-02 14:12 UTCEPSS rescore
  4. 2026-09-02 01:58 UTCEG score recompute
  5. 2026-09-02 01:58 UTCGHSA enrichment
  6. 2026-09-01 13:54 UTCEPSS rescore
  7. 2026-09-01 13:14 UTCEG score recompute
  8. 2026-09-01 13:14 UTCGHSA enrichment
  9. 2026-09-01 04:40 UTCEPSS rescore
  10. 2026-09-01 04:40 UTCEPSS rescore
  11. 2026-09-01 00:29 UTCGHSA enrichment
  12. 2026-08-31 11:43 UTCGHSA enrichment
  13. 2026-08-30 22:52 UTCEG score recompute
  14. 2026-08-30 22:52 UTCGHSA enrichment
  15. 2026-08-30 19:18 UTCEPSS rescore
  16. 2026-08-30 19:17 UTCEPSS rescore
  17. 2026-08-30 10:07 UTCEG score recompute
  18. 2026-08-30 10:06 UTCGHSA enrichment
  19. 2026-08-30 01:22 UTCEPSS rescore
  20. 2026-08-29 21:18 UTCGHSA enrichment
  21. 2026-08-29 08:33 UTCEG score recompute
  22. 2026-08-29 08:32 UTCGHSA enrichment
  23. 2026-08-28 21:42 UTCEPSS rescore
  24. 2026-08-28 10:12 UTCGHSA enrichment
  25. 2026-08-27 20:39 UTCEG score recompute
  26. 2026-08-27 20:39 UTCGHSA enrichment
  27. 2026-08-27 14:25 UTCEPSS rescore
  28. 2026-08-27 07:21 UTCGHSA enrichment
  29. 2026-08-26 17:16 UTCGHSA enrichment
  30. 2026-08-26 16:28 UTCEG score recompute
  31. 2026-08-26 16:28 UTCGHSA enrichment
  32. 2026-08-26 14:47 UTCEPSS rescore
  33. 2026-08-26 03:36 UTCGHSA enrichment
  34. 2026-08-25 14:51 UTCGHSA enrichment
  35. 2026-08-25 02:06 UTCEG score recompute
  36. 2026-08-25 02:06 UTCGHSA enrichment
  37. 2026-08-24 13:22 UTCEG score recompute
  38. 2026-08-24 13:22 UTCGHSA enrichment
  39. 2026-08-24 00:37 UTCGHSA enrichment
  40. 2026-08-23 11:52 UTCGHSA enrichment
  41. 2026-08-22 23:08 UTCGHSA enrichment
  42. 2026-08-22 10:23 UTCEG score recompute
  43. 2026-08-22 10:23 UTCGHSA enrichment
  44. 2026-08-21 23:49 UTCEPSS rescore
  45. 2026-08-21 21:38 UTCGHSA enrichment
  46. 2026-08-21 08:53 UTCGHSA enrichment
  47. 2026-08-20 20:06 UTCGHSA enrichment
  48. 2026-08-20 07:21 UTCGHSA enrichment
  49. 2026-08-19 18:36 UTCEG score recompute
  50. 2026-08-19 18:36 UTCGHSA enrichment
  51. 2026-08-19 17:04 UTCEPSS rescore
  52. 2026-08-19 04:23 UTCGHSA enrichment
  53. 2026-08-18 15:37 UTCEG score recompute
  54. 2026-08-18 15:36 UTCGHSA enrichment
  55. 2026-08-18 13:49 UTCEPSS rescore
  56. 2026-08-18 13:49 UTCEPSS rescore
  57. 2026-08-18 02:47 UTCGHSA enrichment
  58. 2026-08-17 14:02 UTCEG score recompute
  59. 2026-08-17 14:02 UTCGHSA enrichment
  60. 2026-08-17 13:47 UTCEPSS rescore
  61. 2026-08-17 01:18 UTCEG score recompute
  62. 2026-08-17 01:18 UTCGHSA enrichment
  63. 2026-08-16 14:56 UTCEPSS rescore
  64. 2026-08-16 14:56 UTCEPSS rescore
  65. 2026-08-16 12:33 UTCEG score recompute
  66. 2026-08-16 12:33 UTCGHSA enrichment
  67. 2026-08-16 02:15 UTCEPSS rescore
  68. 2026-08-15 23:48 UTCGHSA enrichment
  69. 2026-08-15 11:03 UTCEG score recompute
  70. 2026-08-15 11:03 UTCGHSA enrichment
  71. 2026-08-15 01:31 UTCEPSS rescore
  72. 2026-08-14 22:18 UTCEG score recompute
  73. 2026-08-14 22:18 UTCGHSA enrichment
  74. 2026-08-14 22:14 UTCEG score recompute
  75. 2026-08-14 22:14 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-72809?
CVE-2026-72809 is a high vulnerability published on August 12, 2026. SiYuan versions <= v3.7.2 (patched in v3.7.4) contain an authentication bypass vulnerability in the kernel's CheckAuth function, which grants the administrator role (RoleAdministrator) to any request whose RemoteAddr is loopback (127.0.0.1) for a specific set of endpoints (including…
When was CVE-2026-72809 disclosed?
CVE-2026-72809 was first published in the National Vulnerability Database on August 12, 2026, with the most recent update on August 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-72809 actively exploited?
CVE-2026-72809 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 88.9% of all scored CVEs.
What is the CVSS score of CVE-2026-72809?
CVE-2026-72809 has a CVSS v3 base score of 8.0 (NVD).
How do I remediate CVE-2026-72809?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-72809, 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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