CVE-2025-68948VulnerabilityPublished 27 Dec 2025Updated 29 Dec 2025

CVE-2025-68948: siyuan · Use of Hard-coded Cryptographic Key

Affects siyuanSource CVE Database V5

Not known to be exploited · CVSS 6.9 Medium.

Data as of 26 Oct 2026, 06:15 UTC

CVSS 4.0 base score

6.9Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/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: Low
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
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 27 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 2026-10-25.

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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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

Affected software

Product	Affected	Fixed in
GitHubsiyuan-note/siyuan`pkg:github/siyuan-note/siyuan`Other threats	Affected <=3.5.1	Fixed in–

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AI-suggested

To mitigate CVE-2025-68948, organizations should upgrade SiYuan Note to a version beyond 3.5.1 once a patch is released that removes the hardcoded cryptographic key and implements secure key management practices, such as per-installation unique keys or integration with secure key vaults. Until an official patch is available, organizations should restrict network access to the SiYuan Note instance and enforce strict transport layer security (TLS) to prevent session cookie interception. Implementing HTTP-only and Secure flags on cookies can reduce exposure to client-side attacks. Regularly rotating session secrets and invalidating existing sessions can limit the window of exploitation. Monitoring for unusual session activity or multiple concurrent sessions from different IPs may help detect hijacking attempts. Educating users about the risks of session hijacking and encouraging the use of VPNs or secure networks when accessing SiYuan Note can further reduce risk. Finally, organizations should consider isolating SiYuan Note instances within segmented network zones to limit lateral movement if compromise occurs.

Description

SiYuan is self-hosted, open source personal knowledge management software. In versions 3.5.1 and prior, the SiYuan Note application utilizes a hardcoded cryptographic secret for its session store. This unsafe practice renders the session encryption ineffective. Since the sensitive AccessAuthCode is stored within the session cookie, an attacker who intercepts or obtains a user's encrypted session cookie (e.g., via session hijacking) can locally decrypt it using the public key. Once decrypted, the attacker can retrieve the AccessAuthCode in plain text and use it to authenticate or take over the session.

Impact

For European organizations, this vulnerability threatens the confidentiality and integrity of user sessions within SiYuan Note deployments. Attackers who successfully exploit this flaw can impersonate legitimate users, gaining unauthorized access to sensitive personal knowledge data, potentially leading to data breaches or further lateral movement within an organization’s network. Since SiYuan Note is self-hosted, organizations with less mature security practices or inadequate network protections are at higher risk. The exposure of AccessAuthCode could also facilitate persistent unauthorized access if session tokens are long-lived or not properly invalidated. While availability is not directly impacted, the compromise of user sessions undermines trust and could lead to reputational damage. Organizations relying on SiYuan Note for critical knowledge management should consider this vulnerability a significant risk, especially in sectors handling sensitive or regulated information such as finance, healthcare, or government. The lack of known exploits in the wild provides a window for proactive mitigation before active attacks emerge.

CWE-321Use of Hard-coded Cryptographic Key (opens in a new tab)
Variant weaknessLikelihood of exploit: HighOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product uses a hard-coded, unchangeable cryptographic key.
Architecture and Design
Prevention schemes mirror that of hard-coded password storage.
OWASP Cheat Sheets
Transport Layer Protection (opens in a new tab)
User Privacy Protection (opens in a new tab)
Password Storage (opens in a new tab)
Cryptographic Storage (opens in a new tab)
HSTS (opens in a new tab)
OWASP ASVS 4.0.3
V2.3.1 (opens in a new tab)
V2.6.2 (opens in a new tab)
V2.8.5 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/siyuan-note/siyuan/security/advisories/GHSA-f7ph-rc3w-qp28 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Jan 2026, 22:57 UTC

WeaknessesCWE-321

Technical details

References

Community reviews

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