CVE-2026-63729
MEDIUMTeX Live SyncTeX Parser Heap Use-After-Free via Malformed SyncTeX File
Title source: cnaDescription
The SyncTeX parser (synctex_parser.c) shipped with TeX Live and embedded by downstream consumers such as GNOME Evince contains a heap use-after-free vulnerability that allows attackers to crash applications or potentially execute arbitrary code by supplying a malformed .synctex or .synctex.gz file. A malformed SyncTeX file can construct a ref node with a NULL parent pointer, causing the replacement routine to fail to detach the node from its sibling chain, which triggers recursive freeing of live tree nodes and leaves dangling pointers that are later accessed by the parser during document load.
References (4)
Core 4
Core References
Patch patch
Patch Commit
https://github.com/TeX-Live/texlive-source/commit/002dcd3eac30db5c352f53d4181737961cc7ee9a
Third Party Advisory third-party-advisory
https://www.vulncheck.com/advisories/tex-live-synctex-parser-heap-use-after-free-via-malformed-synctex-file
Scores
CVSS v3
6.6
EPSS
0.0012
EPSS Percentile
2.5%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-416
Status
published
Products (2)
TeX Live/TeX Live
< TeX Live 2025
TeX Live/TeX Live
TeX Live 2026
Published
Jul 21, 2026
Tracked Since
Jul 21, 2026