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Fencer Vulns
high 8.8

CVE-2026-85175 json

SiYuan before v3.8.2 TLS Private Key Disclosure via getFile

published 2026-09-03 2 mo ago modified 2026-10-07 32 d ago also GHSA-4wwp-f6gw-6qm5 , GO-2026-6663 , EUVD-2026-70410

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits
0
none known

Summary

SiYuan versions <= 3.8.1 (fixed in v3.8.2) contain an incomplete blocklist in the IsForbiddenAbsPath() function (kernel/util/path_guard.go), which only blocks conf/conf.json by exact match and does not restrict the TLS private key (conf/key.pem) or CA private key (conf/ca.key) stored in the same conf/ directory. Because the getFile handler skips the blocklist for RoleAdministrator and all authenticated users receive RoleAdministrator in v3.8.1, any user (or any client on a default no-auth-code instance) can retrieve these private keys via POST /api/file/getFile. On deployments with TLS enabled, this allows decryption of captured HTTPS traffic (key.pem) and forging of certificates trusted by clients that imported SiYuan's CA (ca.key).

Patch / fix

  • go github.com/siyuan-note/siyuan/kernel 0.0.0-20260819144130-256d73aa7f94
  • siyuan-note siyuan 3.8.2

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
2 mo ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/siyuan-note/siyuan/security/advisories/GHSA-4wwp-f6gw-6qm5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
go github.com/siyuan-note/siyuan/kernel
<0.0.0-20260819144130-256d73aa7f94
0.0.0-20260819144130-256d73aa7f94

Affected products

  • siyuan-note siyuan

Classification

Weakness
  • CWE-552 Files or Directories Accessible to External Parties

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.