VulnerabilityPublished 12 Aug 2026Updated 14 Aug 2026

CVE-2026-72801: siyuan · Insufficiently Protected Credentials

Affects siyuanSource CVE Database V5

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Not known to be exploited · CVSS 8.7 High : upgrade to 3.7.4 soon.

Data as of 10 Nov 2026, 23:24 UTC

CVSS 4.0 base score

8.7High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.7.4

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade siyuan to 3.7.4.

Affected software

Product	Affected	Fixed in
siyuan-notesiyuan	Affected <3.7.4	Fixed in 3.7.4

AI-suggested

Since the vulnerability affects versions before v3.7.4, upgrading to v3.7.4 or later is likely recommended once confirmed by the vendor. Until then, avoid using publish mode or exposing unauthenticated endpoints that reveal key derivation material.

Description

**CVE:** This vulnerability corresponds to [CVE-2026-72801](https://nvd.nist.gov/vuln/detail/CVE-2026-72801). ### Summary Two `CheckAuth`-only endpoints disclose the complete offline attack material for the encrypted-notebook master password, plus the wrapped per-notebook key needed to use it. Both are reachable by the publish `RoleReader` token and by the anonymous account when `Publish.Auth.Enable` is `false`. An unauthenticated remote client can retrieve the Argon2id salt and cost parameters, a verifier that confirms a correct password offline, and the encrypted per-notebook data key reducing the security of every encrypted notebook to the master password's resistance to offline GPU cracking. ### Details **(1) `POST /api/system/getConf` leaks `NotebookCrypto`.** `getConf` → `GetMaskedConf()` marshals the full configuration including `NotebookCrypto *conf.NotebookCrypto` (JSON tag `notebookCrypto`, not `-`, so it survives the deep copy). For non-administrators `HideConfSecret()` is applied, which nulls a dozen secret-bearing fields like AI, MCPOAuth, Api, Flashcard, Publish, Repo, Sync, Secrets, Variables, System paths but contains **no reference to `NotebookCrypto`**. `FilterConfByPublishIgnore()` for readers only touches `UILayout`. The reader therefore receives: | Field | What it is | |---|---| | `MasterSalt` | global Argon2id salt | | `KDFParams` | Argon2id memory/time/parallelism cost | | `KEKVerifier` + `VerifierNonce` | AES-GCM-encrypted fixed magic, the in-code comment states it exists for offline master-password verification | | `KEKMAC` | HMAC-SHA256 of the KEK | Either `KEKVerifier` or `KEKMAC` is a self-contained offline oracle: ``` KEK = Argon2id(guess, MasterSalt, KDFParams) correct if AES-GCM-decrypt(KEKVerifier, VerifierNonce) == magic or HMAC(KEK) == KEKMAC ``` No server round-trips are required, so there is no rate limiting, lockout, or logging on guesses, and the work is fully GPU-parallelisable. **(2) `POST /api/notebook/getNotebookConf` leaks the wrapped data key.** `box.GetConf()` returns the full `BoxConf` including `BoxCrypt.WrappedDEK`, the per-notebook data-encryption key wrapped under the KEK via AES-GCM together with `WrapNonce`. `getNotebookInfo` is the same class. Once (1) yields the master password, the attacker derives the KEK, decrypts `WrappedDEK` to recover the real data-encryption key, and decrypts every `.sy` file in that notebook. **Why this matters beyond the at-rest threat model.** Storing verifier and KDF material alongside the ciphertext is reasonable against a *local* attacker who already has filesystem access. Serving `MasterSalt` + `KDFParams` + `KEKVerifier` + `WrappedDEK` to an *anonymous remote reader* converts that at-rest assumption into a remote pre-authentication cracking opportunity. **Guarded-sibling asymmetry.** `HideConfSecret` nulls a dozen secret fields but omits `NotebookCrypto`. `lsNotebooks` filters notebook visibility for readers, while `getNotebookConf` and `getNotebookInfo` apply no reader filter at all. Verified at `origin/master` (`eef105683`): handler bodies as described; `HideConfSecret` contains zero `NotebookCrypto` matches; `FilterConfByPublishIgnore` touches only `UILayout`; all relevant struct JSON tags are non-`-`; all three routes are registered `CheckAuth` without `CheckAdminRole`. ### Proof of Concept Precondition: publish mode enabled (default port 6808) with at least one encrypted notebook configured; anonymous when `Publish.Auth.Enable` is `false`, otherwise any publish reader account. **1. Retrieve the key-derivation material as an anonymous reader:** ``` POST http://127.0.0.1:6808/api/system/getConf {} ``` The response's `notebookCrypto` object contains `MasterSalt`, `KDFParams`, `KEKVerifier`, `VerifierNonce`, and `KEKMAC` while the same response has the other secret fields (Api, Repo, Sync, Publish, System paths) correctly blanked, demonstrating the omission. **2. Retrieve the wrapped notebook key:** ``` POST http://127.0.0.1:6808/api/notebook/getNotebookConf {"notebook":"<NOTEBOOK_ID>"} ``` The response contains `BoxCrypt.WrappedDEK` and `WrapNonce`. **3. Offline:** candidate passwords are verified locally against `KEKVerifier`/`KEKMAC` using `MasterSalt` and `KDFParams`, with no further server interaction. A recovered password yields the KEK, which unwraps `WrappedDEK` to the notebook's data-encryption key. *Verification status:* the leak paths are confirmed by code inspection at `origin/master`. A live end-to-end demonstration requires a build from HEAD with an encrypted notebook enabled; the test instance available predates the encrypted-notebook feature, so no runtime reproduction is claimed here. ### Impact An unauthenticated remote client (publish mode with auth disabled) or any publish `RoleReader` obtains everything needed to mount an unlimited, unthrottled, GPU-parallel offline attack on the encrypted-notebook master password, plus the wrapped data key to decrypt notebook contents o

Impact

An attacker can obtain key derivation parameters and wrapped keys without authentication, enabling unlimited offline brute-force attacks on the master password. This compromises the confidentiality of encrypted notebooks. There is no indication of privilege escalation or integrity/availability impact. No known exploits in the wild have been reported.

Summary

CVE-2026-72801 affects SiYuan note-taking software versions prior to v3.7.4. The vulnerability arises because encrypted-notebook key-derivation material and wrapped data keys are disclosed through unauthenticated endpoints when the software is in publish mode. Attackers can retrieve sensitive cryptographic parameters including Argon2id salt, cost parameters, password verifiers, and wrapped notebook keys. This exposure allows attackers to conduct unlimited offline cracking of the master password without any rate limiting or authentication barriers. The CVSS 4.0 score is 8.7, reflecting network attack vector, low attack complexity, no privileges or user interaction required, and high impact on confidentiality.

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Affected software

Description

AI analysisMachine-generated, updated 12 Aug 2026, 19:43 UTC

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