6.8
MEDIUM CVSS 4.0
CVE-2026-63729
TeX Live SyncTeX Parser Heap Use-After-Free via Malformed SyncTeX File
Description

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.

INFO

Published Date :

July 21, 2026, 3:16 a.m.

Last Modified :

July 21, 2026, 3:16 a.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-63729 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Update SyncTeX parser to fix heap use-after-free vulnerability.
  • Update the SyncTeX parser component.
  • Recompile applications that use the parser.
  • Avoid processing untrusted .synctex files.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-63729 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-63729 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-63729 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-63729 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 21, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'TeX Live', 'product': 'TeX Live', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': 'TeX Live 2025'}, {'status': 'unaffected', 'version': 'TeX Live 2026', 'versionType': 'custom'}], 'defaultStatus': 'affected'}]
    Added Description 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.
    Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
    Added CWE CWE-416
    Added Reference https://fatihhcelik.github.io/posts/evince-synctex-heap-use-after-free/
    Added Reference https://github.com/TeX-Live/texlive-source/
    Added Reference https://github.com/TeX-Live/texlive-source/commit/002dcd3eac30db5c352f53d4181737961cc7ee9a
    Added Reference https://www.vulncheck.com/advisories/tex-live-synctex-parser-heap-use-after-free-via-malformed-synctex-file
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.