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.
CVE-2026-63729
MEDIUMPre-NVD 6.66.6—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 6.6 from GitHub Security Advisory published 2026-07-21. a secondary CVSS source baseline 6.6; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
6.6
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.6Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.6
- EG Score
- 6.6(high)
- EG Risk
- 30(Track)EG Risk 30/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity66% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 2.5%
- KEV
- Not listed
Published
July 21, 2026
Last Modified
July 23, 2026
Advisory Details (4)
Auto-updated Jul 21, 2026Upstream fix merged — awaiting tagged release. Sources: github_commit.
generic
TeX Live SyncTeX Parser Heap Use-After-Free via Malformed SyncTeX File | Advisories | VulnCheck
https://www.vulncheck.com/advisories/tex-live-synctex-parser-heap-use-after-free-via-malformed-synctex-filegithub_commit
commit 002dcd3eac30 (TeX-Live/texlive-source)
Fix landed in TeX-Live/texlive-source commit 002dcd3eac30 — awaiting tagged release
https://github.com/TeX-Live/texlive-source/commit/002dcd3eac30db5c352f53d4181737961cc7ee9ageneric
GitHub - TeX-Live/texlive-source: source part of the TeX Live subversion repository - for issues please contact the tex-k mailing list at tug.org · GitHub
https://github.com/TeX-Live/texlive-source/generic
Use-After-Free in SyncTeX Parser | Fatih's Blog
https://fatihhcelik.github.io/posts/evince-synctex-heap-use-after-free/Vendor Advisories for CVE-2026-63729(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 15× in last 7d / 15× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:22 UTCEG score recompute
- 2026-07-22 23:23 UTCEG score recompute
- 2026-07-22 23:23 UTCGHSA enrichment
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-21 14:12 UTCEG score recompute
- 2026-07-21 14:12 UTCGHSA enrichment
- 2026-07-21 03:51 UTCEG score recompute
- 2026-07-21 03:51 UTCGHSA enrichment
- 2026-07-21 02:17 UTCEG score recompute
- 2026-07-21 02:17 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-416
- CVE-2010-3962NVD 8.1EG 9.0 KEVEPSS 100%HIGH
- CVE-2010-0806NVD 8.8EG 9.0 KEVEPSS 100%HIGH
- CVE-2010-0249NVD 8.8EG 9.0 KEVEPSS 100%HIGH
- CVE-2009-4324NVD 7.8EG 9.0 KEVEPSS 100%HIGH
- CVE-2010-3328EG 8.8EPSS 98%HIGH
- CVE-2010-1772EG 8.8HIGH
- CVE-2010-1208EG 8.8EPSS 92%HIGH
- CVE-2010-0050EG 8.8EPSS 96%HIGH
- CVE-2010-0378EG 8.8EPSS 93%HIGH
- CVE-2009-3658EG 8.8EPSS 95%HIGH
Frequently asked(5)
What is CVE-2026-63729?
CVE-2026-63729 is a medium vulnerability published on July 21, 2026. 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.…
When was CVE-2026-63729 disclosed?
CVE-2026-63729 was first published in the National Vulnerability Database on July 21, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63729 actively exploited?
CVE-2026-63729 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-63729?
CVE-2026-63729 has a CVSS v3 base score of 6.6 (NVD).
How do I remediate CVE-2026-63729?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63729, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-63729
Is Your Infrastructure Affected by CVE-2026-63729?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.