CVE-2026-25539

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-01-29. NVD baseline CVSS 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.1Exploit: NoneExposed: 0

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

SiYuan is a personal knowledge management system. Prior to version 3.5.5, the /api/file/copyFile endpoint does not validate the dest parameter, allowing authenticated users to write files to arbitrary locations on the filesystem. This can lead to Remote Code Execution (RCE) by writing to sensitive locations such as cron jobs, SSH authorized_keys, or shell configuration files. This issue has been patched in version 3.5.5.

CVSS v3
9.1
EG Score
9.1(medium)
EPSS
59.4%
KEV
Not listed

Published

February 4, 2026

Last Modified

February 11, 2026

Advisory Details (2)

Auto-updated Jun 7, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github Patch Available🟡 PoC Available

Arbitrary File Write via /api/file/copyFile leading to RCE · Advisory · siyuan-note/siyuan · GitHub

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-c4jr-5q7w-f6r9
github_commit

commit d7f790755edf (siyuan-note/siyuan)

Fix landed in siyuan-note/siyuan commit d7f790755edf — awaiting tagged release

https://github.com/siyuan-note/siyuan/commit/d7f790755edf8c78d2b4176171e5a0cdcd720feb

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
gogithub.com/siyuan-note/siyuan/kernel—ghsa

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.

Affected Packages

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

Weakness Classification(1)

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

Data Freshness Timeline

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

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-25539?
CVE-2026-25539 is a critical vulnerability published on February 4, 2026. SiYuan is a personal knowledge management system. Prior to version 3.5.5, the /api/file/copyFile endpoint does not validate the dest parameter, allowing authenticated users to write files to arbitrary locations on the filesystem. This can lead to Remote Code Execution (RCE) by writing to sensitive…
When was CVE-2026-25539 disclosed?
CVE-2026-25539 was first published in the National Vulnerability Database on February 4, 2026, with the most recent update on February 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-25539 actively exploited?
CVE-2026-25539 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 59.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-25539?
CVE-2026-25539 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-25539?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-25539, 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.

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