How severe is CVE-2026-34453?

CVE-2026-34453 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-34453 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34453?

CVE-2026-34453 affects B3log Siyuan. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34453?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-34453 have an EU (EUVD) identifier?

Yes. CVE-2026-34453 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17683.

When was CVE-2026-34453 published?

CVE-2026-34453 was published on 2026-03-31 and last updated on 2026-06-17.

CVE-2026-34453

CVE-2026-34453 is a high-severity vulnerability in B3log Siyuan with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-17683
Weakness: CWE-863
Affected product: B3log Siyuan
Published: 2026-03-31
Last modified: 2026-06-17

Description

SiYuan is a personal knowledge management system. Prior to version 3.6.2, the publish service exposes bookmarked blocks from password-protected documents to unauthenticated visitors. In publish/read-only mode, /api/bookmark/getBookmark filters bookmark results by calling FilterBlocksByPublishAccess(nil, ...). Because the filter treats a nil context as authorized, it skips the publish password check and returns bookmarked blocks from documents configured as Protected. As a result, anyone who can access the publish service can retrieve content from protected documents without providing the required password, as long as at least one block in the document is bookmarked. This issue has been patched in version 3.6.2.

Frequently asked questions

What is CVE-2026-34453?: SiYuan is a personal knowledge management system. Prior to version 3.6.2, the publish service exposes bookmarked blocks from password-protected documents to unauthenticated visitors. In publish/read-only mode, /api/bookmark/getBookmark filters bookmark results by calling FilterBlocksByPublishAccess(nil, ...). Because the filter treats a nil context as authorized, it skips the publish password check and returns bookmarked blocks from documents configured as Protected. As a result, anyone who can access the publish service can retrieve content from protected documents without providing the required password, as long as at least one block in the document is bookmarked. This issue has been patched in version 3.6.2.
How severe is CVE-2026-34453?: CVE-2026-34453 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-34453 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34453?: CVE-2026-34453 affects B3log Siyuan. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34453?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-34453 have an EU (EUVD) identifier?: Yes. CVE-2026-34453 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17683.
When was CVE-2026-34453 published?: CVE-2026-34453 was published on 2026-03-31 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*

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