# Libexpat Project Expat vulnerabilities

Source: https://junglewise.ai/threats/technologies/expat  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Updated: 9 November 2026, 03:07 UTC. Rebuilt every hour.  
Data: https://junglewise.ai/threats/technologies/expat.json  
License: CC BY 4.0 with a link back

Junglewise Threat Intelligence has tracked 22 vulnerabilities in Libexpat Project Expat: 0 in the last 7 days and 3 in the last 90 days, 0 of them critical and 0 exploited in the wild. The most recent, CVE-2026-76641, was published on 20 August 2026. Nothing was published in the last eight weeks.

## Counts

- Last 7 days: 0
- Last 30 days: 0
- Last 90 days: 3
- All time: 22 (0 critical, 0 exploited in the wild)

## About Libexpat Project Expat

C library for parsing XML documents.

## Latest Libexpat Project Expat vulnerabilities

- [CVE-2026-76641: Expat out-of-bounds read in XML parser](https://junglewise.ai/threats/cve-2026-76641-expat-out-of-bounds-read-in-xml-parser) (high, CVSS 7.5, published 20 Aug 2026)
- [CVE-2026-76957: libexpat use-after-free in custom encoding callbacks](https://junglewise.ai/threats/cve-2026-76957-libexpat-use-after-free-in-custom-encoding-callbacks) (medium, CVSS 4.9, published 20 Aug 2026)
- [CVE-2026-66046: Expat XML parser denial of service via quadratic complexity](https://junglewise.ai/threats/cve-2026-66046-expat-xml-parser-denial-of-service-via-quadratic-complexity) (high, CVSS 7.5, published 18 Aug 2026)
- [CVE-2026-56412: libexpat use-after-free in doCdataSection](https://junglewise.ai/threats/cve-2026-56412-libexpat-use-after-free-in-docdatasection) (medium, CVSS 4.9, published 21 Jun 2026)
- [CVE-2026-56411: libexpat integer overflow in xmlwf endDoctypeDecl](https://junglewise.ai/threats/cve-2026-56411-libexpat-integer-overflow-in-xmlwf-enddoctypedecl) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56410: libexpat xmlwf integer overflow in resolveSystemId](https://junglewise.ai/threats/cve-2026-56410-libexpat-xmlwf-integer-overflow-in-resolvesystemid) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56409: libexpat xmlwf integer overflow in output filename handling](https://junglewise.ai/threats/cve-2026-56409-libexpat-xmlwf-integer-overflow-in-output-filename-handling) (medium, CVSS 6.5, published 21 Jun 2026)
- [CVE-2026-56408: libexpat integer overflow in copyString](https://junglewise.ai/threats/cve-2026-56408-libexpat-integer-overflow-in-copystring) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56407: libexpat integer overflow in doProlog entity handling](https://junglewise.ai/threats/cve-2026-56407-libexpat-integer-overflow-in-doprolog-entity-handling) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56406: libexpat integer overflow in XML_ParseBuffer](https://junglewise.ai/threats/cve-2026-56406-libexpat-integer-overflow-in-xml-parsebuffer) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56405: libexpat integer overflow in getAttributeId](https://junglewise.ai/threats/cve-2026-56405-libexpat-integer-overflow-in-getattributeid) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56404: libexpat integer overflow in addBinding](https://junglewise.ai/threats/cve-2026-56404-libexpat-integer-overflow-in-addbinding) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56403: libexpat integer overflow in storeAtts](https://junglewise.ai/threats/cve-2026-56403-libexpat-integer-overflow-in-storeatts) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56132: libexpat heap buffer overflow in doProlog](https://junglewise.ai/threats/cve-2026-56132-libexpat-heap-buffer-overflow-in-doprolog) (medium, CVSS 6.9, published 19 Jun 2026)
- [CVE-2026-56131: libexpat use-after-free in XML_ResumeParser](https://junglewise.ai/threats/cve-2026-56131-libexpat-use-after-free-in-xml-resumeparser) (medium, CVSS 4.9, published 19 Jun 2026)
- [CVE-2026-50219: libexpat use-after-free via insufficient handler call depth tracking](https://junglewise.ai/threats/cve-2026-50219-libexpat-use-after-free-via-insufficient-handler-call-depth) (medium, CVSS 4.9, published 4 Jun 2026)
- [CVE-2026-45186: libexpat denial of service via attribute name collision check](https://junglewise.ai/threats/cve-2026-45186-libexpat-denial-of-service-via-attribute-name-collision-check) (low, CVSS 2.9, published 10 May 2026)
- [CVE-2026-32778: libexpat NULL pointer dereference in setContext function](https://junglewise.ai/threats/cve-2026-32778-libexpat-null-pointer-dereference-in-setcontext-function) (low, CVSS 2.9, published 16 Mar 2026)
- [CVE-2026-32777: libexpat infinite loop in entityValueProcessor during DTD parsing](https://junglewise.ai/threats/cve-2026-32777-libexpat-infinite-loop-in-entityvalueprocessor-during-dtd-parsing) (medium, CVSS 4, published 16 Mar 2026)
- [CVE-2026-25210: libexpat integer overflow in doContent tag buffer reallocation](https://junglewise.ai/threats/cve-2026-25210-libexpat-integer-overflow-in-docontent-tag-buffer-reallocation) (medium, CVSS 6.9, published 30 Jan 2026)
- [CVE-2026-24515: libexpat NULL pointer dereference in XML_ExternalEntityParserCreate](https://junglewise.ai/threats/cve-2026-24515-libexpat-null-pointer-dereference-in-xml) (low, CVSS 2.9, published 23 Jan 2026)
- [CVE-2025-59375: libexpat Expat resource exhaustion in XML parsing](https://junglewise.ai/threats/cve-2025-59375-libexpat-expat-resource-exhaustion-in-xml-parsing) (high, CVSS 7.5, published 15 Sep 2025)

## Most severe Libexpat Project Expat vulnerabilities

- [CVE-2026-66046: Expat XML parser denial of service via quadratic complexity](https://junglewise.ai/threats/cve-2026-66046-expat-xml-parser-denial-of-service-via-quadratic-complexity) (high, CVSS 7.5, published 18 Aug 2026)
- [CVE-2026-76641: Expat out-of-bounds read in XML parser](https://junglewise.ai/threats/cve-2026-76641-expat-out-of-bounds-read-in-xml-parser) (high, CVSS 7.5, published 20 Aug 2026)
- [CVE-2025-59375: libexpat Expat resource exhaustion in XML parsing](https://junglewise.ai/threats/cve-2025-59375-libexpat-expat-resource-exhaustion-in-xml-parsing) (high, CVSS 7.5, published 15 Sep 2025)
- [CVE-2026-25210: libexpat integer overflow in doContent tag buffer reallocation](https://junglewise.ai/threats/cve-2026-25210-libexpat-integer-overflow-in-docontent-tag-buffer-reallocation) (medium, CVSS 6.9, published 30 Jan 2026)
- [CVE-2026-56411: libexpat integer overflow in xmlwf endDoctypeDecl](https://junglewise.ai/threats/cve-2026-56411-libexpat-integer-overflow-in-xmlwf-enddoctypedecl) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56410: libexpat xmlwf integer overflow in resolveSystemId](https://junglewise.ai/threats/cve-2026-56410-libexpat-xmlwf-integer-overflow-in-resolvesystemid) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56408: libexpat integer overflow in copyString](https://junglewise.ai/threats/cve-2026-56408-libexpat-integer-overflow-in-copystring) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56407: libexpat integer overflow in doProlog entity handling](https://junglewise.ai/threats/cve-2026-56407-libexpat-integer-overflow-in-doprolog-entity-handling) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56406: libexpat integer overflow in XML_ParseBuffer](https://junglewise.ai/threats/cve-2026-56406-libexpat-integer-overflow-in-xml-parsebuffer) (medium, CVSS 6.9, published 21 Jun 2026)
- [CVE-2026-56405: libexpat integer overflow in getAttributeId](https://junglewise.ai/threats/cve-2026-56405-libexpat-integer-overflow-in-getattributeid) (medium, CVSS 6.9, published 21 Jun 2026)

## Vulnerabilities per week

Nothing was published in the last eight weeks.

| Week of | Vulns | Critical | Exploited |
| --- | --- | --- | --- |
| 17 Aug 2026 | 3 | 0 | 0 |
| 24 Aug 2026 | 0 | 0 | 0 |
| 31 Aug 2026 | 0 | 0 | 0 |
| 7 Sep 2026 | 0 | 0 | 0 |
| 14 Sep 2026 | 0 | 0 | 0 |
| 21 Sep 2026 | 0 | 0 | 0 |
| 28 Sep 2026 | 0 | 0 | 0 |
| 5 Oct 2026 | 0 | 0 | 0 |
| 12 Oct 2026 | 0 | 0 | 0 |
| 19 Oct 2026 | 0 | 0 | 0 |
| 26 Oct 2026 | 0 | 0 | 0 |
| 2 Nov 2026 | 0 | 0 | 0 |
| 9 Nov 2026 | 0 | 0 | 0 |

## Other Libexpat Project technologies

- [Libexpat Project Libexpat](https://junglewise.ai/threats/technologies/libexpat): 30 vulnerabilities

## Sources

NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories. Rebuilt every hour. Cite as: Junglewise Threat Intelligence, "Libexpat Project Expat vulnerabilities", https://junglewise.ai/threats/technologies/expat, 9 November 2026.