CVE-2024-40433Public exploitNetwork attack vector

Authentication bypass via shared web-view cookie storage

Published Jul 26, 2024 · Updated Aug 2, 2024

Cookie isolation failure in Tencent WeChat 8.0.37 allows attackers to obtain another mini-program's session cookies through web-view. On iOS, every mini-program web-view writes cookies to the same Cookies.binarycookies file under the WeChat Library/Cookies directory instead of isolating storage per mini-program. Exploitation requires two mini-programs to embed H5 pages from the same domain; the second can inherit login state and bypass the super-app authorization boundary without the account holder noticing.

CVSS severity8.8
High
EPSS probability1.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cookie isolation failure in Tencent WeChat 8.0.37 allows attackers to obtain another mini-program's session cookies through web-view. On iOS, every mini-program web-view writes cookies to the same Cookies.binarycookies file under the WeChat Library/Cookies directory instead of isolating storage per mini-program. Exploitation requires two mini-programs to embed H5 pages from the same domain; the second can inherit login state and bypass the super-app authorization boundary without the account holder noticing.

The record

CVE
CVE-2024-40433
Published
Jul 26, 2024
Updated
Aug 2, 2024
Vendor
Tencent
Product
WeChat
Classifications
CWE-266, T1550.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 26, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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=8.0.37

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Tencent · WeChatversion=8.0.37

Published CVSS scores

8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-266Incorrect Privilege Assignment
T1550.004Use Alternate Authentication Material: Web Session Cookie

Public exploit references

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Technologies

Your stack

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Your stack

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