CVE-2026-43862
Improper GSSAPI Authentication Handling in Mutt
Publication date: 2026-05-04
Last updated on: 2026-05-04
Assigner: MITRE
Description
Description
CVSS Scores
EPSS Scores
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| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| muttmua | mutt | to 2.3.2 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-843 | The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the Mutt email client before version 2.3.2, specifically in the imap_auth_gss() function. The issue is due to improper handling of the security level data during GSSAPI authentication, including insufficient size checks and incorrect data type usage. This could lead to unsafe memory operations such as buffer overflows or undefined behavior, especially on 64-bit systems where data types were mismatched.
The fix involved adding a check to ensure the token length is at least 4 bytes before processing, and changing the buffer size variable to a proper 32-bit unsigned integer type to match the expected data size, improving memory safety and correctness.
How can this vulnerability impact me? :
This vulnerability can impact you by potentially allowing improper handling of authentication data during IMAP GSSAPI authentication in Mutt. While the CVSS score is relatively low (3.7), indicating limited severity, the improper size and type handling could lead to minor integrity issues or unexpected behavior in the authentication process.
However, there is no indication of confidentiality or availability impact, and the vulnerability requires network access with high attack complexity and no privileges or user interaction.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
There is no specific information provided about detection methods or commands to identify this vulnerability on your network or system.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, update the Mutt email client to version 2.3.2 or later where the issue in the imap_auth_gss() function has been fixed.
- Ensure that the fix includes proper size checks to prevent buffer overflows during GSSAPI authentication.
- Verify that the data types used in the authentication process are correctly handled, particularly the use of 32-bit unsigned integers.
- Avoid using vulnerable versions of Mutt prior to 2.3.2.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify any direct impact of this vulnerability on compliance with common standards and regulations such as GDPR or HIPAA.