CVE-2026-63729

6.8 MEDIUM 0.2% exploit odds Fix listed Memory safety Device

What it is

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.

At a glance

Exploitability: Can be exploited locally on the machine without logging in, but needs a user to act. High risk of service disruption.
Exploit odds: 0.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-07-21 03:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-07-23 15:24 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.2% in the next 30 days (EPSS).
Severity: 6.8 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-07-21 03:16 UTC
Last modified: 2026-07-23 15:24 UTC
Exploit probability: 0.2% · EPSS, next 30 days
Weakness: CWE-416 · Use after free
Record status: Deferred

Attack profile CVSS 4.0 · 6.8

Attack vector: Local
Complexity: Low
Attack requirements: None
Privileges needed: None
User interaction: Active
Confidentiality: Low
Integrity: Low
Availability: High

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-63729.md and follow it. Check whether this project is affected by CVE-2026-63729. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

https://github.com/TeX-Live/texlive-source/commit/002dcd3eac30db5c352f53d4181737961cc7ee9a

References

NVD record · CVE.org record