CVE-2023-4696Network attack vector

Unauthenticated account takeover via unvalidated JWT signatures

Published Sep 1, 2023 · Updated Sep 30, 2024

Improper access control in Memos before 0.13.2 allows remote attackers to take over accounts by submitting forged access tokens. JWTMiddleware parses bearer-token claims but fails to reject a token whose HS256 signature validation leaves accessToken.Valid false. A forged token with the access-token audience and an existing user's subject reaches protected routes with that user's privileges.

CVSS severity9.8
Critical
EPSS probability1.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Memos before 0.13.2 allows remote attackers to take over accounts by submitting forged access tokens. JWTMiddleware parses bearer-token claims but fails to reject a token whose HS256 signature validation leaves accessToken.Valid false. A forged token with the access-token audience and an existing user's subject reaches protected routes with that user's privileges.

The record

CVE
CVE-2023-4696
Published
Sep 1, 2023
Updated
Sep 30, 2024
Vendor
Memos
Product
Memos
Classifications
CWE-284, T1550.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 1, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 30, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <0.13.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Memos · Memosversion=unspecified <0.13.2

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8huntr.devCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1550.001Application Access Token

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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