CVE-2026-25920
Heap Out-of-Bounds Read in SumatraPDF MOBI Decompressor Causes Crash
Publication date: 2026-02-09
Last updated on: 2026-02-20
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| sumatrapdfreader | sumatrapdf | to 3.5.2 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-125 | The product reads data past the end, or before the beginning, of the intended buffer. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in SumatraPDF version 3.5.2 and earlier, specifically in the MOBI HuffDic decompressor component. The issue is a heap out-of-bounds read caused by improper bounds checking in the AddCdicData() function. This function only validates half the range that the DecodeOne() function actually accesses. As a result, when a specially crafted .mobi file is opened, the program can read memory beyond the intended CDIC dictionary buffer.
This out-of-bounds read can lead to a crash of the SumatraPDF application.
How can this vulnerability impact me? :
The primary impact of this vulnerability is that opening a maliciously crafted .mobi file can cause SumatraPDF to crash due to the heap out-of-bounds read. This results in a denial of service (DoS) condition where the application becomes unavailable or unstable.
There is no indication from the provided information that this vulnerability leads to information disclosure, privilege escalation, or code execution.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know