Local process crash via CFF offset misvalidation
Published Apr 28, 2026 · Updated Apr 28, 2026
Out-of-bounds read in MuPDF 1.28.0 and earlier allows local users to crash mutool by processing a crafted PDF containing a CFF font. index_load validates a relative CFF INDEX offset against the full buffer length, but index_get adds data_offset before do_subset uses the result in memcpy. A local user must invoke font subsetting on the file; the demonstrated result is a process crash, and adjacent heap bytes can be copied into the output.
Summary
What happened
Out-of-bounds read in MuPDF 1.28.0 and earlier allows local users to crash mutool by processing a crafted PDF containing a CFF font. index_load validates a relative CFF INDEX offset against the full buffer length, but index_get adds data_offset before do_subset uses the result in memcpy. A local user must invoke font subsetting on the file; the demonstrated result is a process crash, and adjacent heap bytes can be copied into the output.
The record
- CVE
- CVE-2026-7233
- Published
- Apr 28, 2026
- Updated
- Apr 28, 2026
- Vendor
- Artifex Software, Inc.
- Product
- MuPDF
- Classifications
- CWE-119, CWE-125, T1203
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 28, 2026CVE publishedPublication date reported by the CVE source.
- Apr 28, 2026Record 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.
- Affected versionversion=1.0
- Affected versionversion=1.1
- Affected versionversion=1.10
- Affected versionversion=1.11
- Affected versionversion=1.12
- Affected versionversion=1.13
- Affected versionversion=1.14
- Affected versionversion=1.15
- Affected versionversion=1.16
- Affected versionversion=1.17
- Affected versionversion=1.18
- Affected versionversion=1.19
- Affected versionversion=1.2
- Affected versionversion=1.20
- Affected versionversion=1.21
- Affected versionversion=1.22
- Affected versionversion=1.23
- Affected versionversion=1.24
- Affected versionversion=1.25
- Affected versionversion=1.26
- Affected versionversion=1.27
- Affected versionversion=1.28.0
- Affected versionversion=1.3
- Affected versionversion=1.4
- Affected versionversion=1.5
- Affected versionversion=1.6
- Affected versionversion=1.7
- Affected versionversion=1.8
- Affected versionversion=1.9
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- MuPDF CFF INDEX out-of-bounds-read reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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