CVE-2024-21635VulnerabilityPublished 14 Nov 2025

CVE-2024-21635: usememos memos · Improper Authentication

Affects usememos memosSource CVE Database V5

Not known to be exploited · CVSS 7.1 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

7.1High

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.

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: High
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: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 14 Nov 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
GitHubusememos/memos`pkg:github/usememos/memos`Other threats	Affected <=0.18.1	Fixed in–

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AI-suggested

Until an official patch is released, European organizations should implement the following mitigations: 1) Educate users to manually review and revoke all Access Tokens after any password change to eliminate unauthorized sessions. 2) Implement monitoring and alerting for unusual token usage patterns or access from unfamiliar devices or locations. 3) Enforce multi-factor authentication (MFA) on memos accounts to reduce the risk of initial token compromise. 4) Limit the lifespan of Access Tokens where possible by configuring shorter expiration times if supported. 5) Encourage users to regularly audit their active tokens and remove any that are unknown or suspicious. 6) Consider isolating memos usage to less sensitive environments or restricting network access until a patch is available. 7) Engage with the usememos project or community to track patch releases and apply updates promptly. 8) Review and enhance internal incident response procedures to handle token compromise scenarios effectively.

Description

Memos is a privacy-first, lightweight note-taking service that uses Access Tokens to authenticate application access. When a user changes their password, the existing list of Access Tokens stay valid instead of expiring. If a user finds that their account has been compromised, they can update their password. In versions up to and including 0.18.1, though, the bad actor will still have access to their account because the bad actor's Access Token stays on the list as a valid token. The user will have to manually delete the bad actor's Access Token to secure their account. The list of Access Tokens has a generic Description which makes it hard to pinpoint a bad actor in a list of Access Tokens. A known patched version of Memos isn't available. To improve Memos security, all Access Tokens will need to be revoked when a user changes their password. This removes the session for all the user's devices and prompts the user to log in again. One can treat the old Access Tokens as "invalid" because those Access Tokens were created with the older password.

Impact

For European organizations using memos, this vulnerability poses a significant risk of persistent unauthorized access to sensitive notes and data. Attackers who gain access to an account can maintain access indefinitely, even after password resets, potentially leading to data breaches, intellectual property theft, or exposure of confidential information. The inability to automatically revoke tokens increases the window of exposure and complicates incident response. Organizations relying on memos for internal communications or sensitive note-taking may face compliance risks under GDPR if personal or sensitive data is compromised. The generic token descriptions hinder quick detection and remediation, increasing operational overhead. Additionally, the lack of a patch means organizations must rely on manual controls and monitoring, which may not be feasible at scale. This vulnerability could also be exploited in targeted attacks against high-value individuals or departments within European companies, especially those in sectors like finance, legal, or government where note confidentiality is critical.

Summary

CVE-2024-21635 affects the usememos memos application, a privacy-focused note-taking service that authenticates users via Access Tokens. In versions up to and including 0.18.1, when a user changes their password, the system fails to invalidate existing Access Tokens. This improper authentication flaw (CWE-287) means that any previously issued tokens remain valid, allowing an attacker who has obtained a token to retain access despite a password reset. The tokens are generically described, making it difficult for users or administrators to identify and revoke malicious tokens. The vulnerability does not require user interaction or elevated privileges, and the attacker can maintain persistent access to the victim’s account, compromising confidentiality and integrity of stored notes. The CVSS 7.1 score reflects the network attack vector, low attack complexity, no privileges or user interaction needed, and high impact on confidentiality and integrity. This flaw undermines the security model of memos by not properly tying token validity to password changes, which is a fundamental security expectation in token-based authentication systems.

CWE-287Improper Authentication (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Libraries or Frameworks
Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
Attack patterns
Fake the Source of Data (opens in a new tab)
Utilizing REST's Trust in the System Resource to Obtain Sensitive Data (opens in a new tab)
Session Hijacking (opens in a new tab)
Token Impersonation (opens in a new tab)
Upload a Web Shell to a Web Server (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/usememos/memos/security/advisories/GHSA-mr34-8733-grr2 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 21 Nov 2025, 15:08 UTC

WeaknessesCWE-287

Technical details

References

Community reviews

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