Skip to content
Fencer Intel
medium 6.6

CVE-2026-63729 json

TeX Live SyncTeX Parser Heap Use-After-Free via Malformed SyncTeX File

published 3mo ago modified last mo. also EUVD-2026-46144

cvss
6.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

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.

Patch / fix

  • TeX Live TeX Live TeX Live 2026
  • texstudio Debian 14 4.9.6+ds-1
  • texlive-bin Debian 14 2026.20260303.78225+ds-2

debian advisories DEBIAN-CVE-2026-63729

  • texlive SLE Module for Desktop Applications 15 SP7, SLE Module for Basesystem 15 SP7 2021.20210325-150600.38.3.1
  • evince SLE Module for Desktop Applications 15 SP7 45.0-150600.3.6.1
  • texlive SLES LTSS Extended Security 12 SP5 2013.20130620-22.14.1

suse advisories SUSE-SU-2026:3924-1SUSE-SU-2026:3628-1SUSE-SU-2026:3512-1

  • evince openSUSE Tumbleweed 48.4-2.1

opensuse advisories openSUSE-SU-2026:11412-1

Is CVE-2026-63729 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-63729 updated cvss 6.6

texlive: evince: TeX Live SyncTeX Parser: Heap use-after-free allows arbitrary code execution via malformed file

  • Red Hat Enterprise Linux 6 evince, mendexk, texlive, kpathsea, evince-dvi, evince-libs, +8 more Red Hat Enterprise Linux 7 evince, texlive, evince-dvi, texlive-ae, texlive-cm, texlive-ec, +309 more Red Hat Enterprise Linux 8 evince, texlive, texlive-ae, texlive-cm, texlive-ec, texlive-fp, +315 more Red Hat Enterprise Linux 9 evince, texlive, texlive-ae, texlive-cm, texlive-ec, texlive-fp, +368 more Red Hat Enterprise Linux 10 texlive
    affected: no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 6.8 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
CNA 3.1 6.6 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
CNA 4.0 6.8 CVSS:4.0/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

Affected products

  • TeX Live TeX Live

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.