CVE-2026-56404
published 2026-06-21CVE-2026-56404: libexpat before 2.8.2 has an integer overflow in addBinding.
PriorityP432medium6.9CVSS 3.1
AVLACHPRNUINSUCHIHAL
EPSS
0.13%
2.6th percentile
libexpat before 2.8.2 has an integer overflow in addBinding.
Affected
7 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | expat | — | — |
| debian | xmlrpc-c | — | — |
| libexpat_project | libexpat | < 2.8.2 | 2.8.2 |
| mozilla | firefox | — | — |
| mozilla | thunderbird | — | — |
| ubuntu | expat | — | — |
| ubuntu | libxmltok | — | — |
CVSS provenance
nvdv3.16.9MEDIUMCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
vendor_ubuntu7.5HIGH
vendor_redhat6.9MEDIUM
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VulDB
libexpat up to 2.8.1 integer overflow (EUVD-2026-38181)
vuldb·2026-06-21·CVSS 6.9
CVE-2026-56404 [MEDIUM] libexpat up to 2.8.1 integer overflow (EUVD-2026-38181)
A vulnerability classified as problematic was found in libexpat up to 2.8.1. This affects an unknown part. Such manipulation leads to integer overflow.
This vulnerability is listed as CVE-2026-56404. The attack must be carried out locally. There is no available exploit.
Upgrading the affected component is advised.
GHSA
libexpat before 2.8.2 has an integer overflow in addBinding.
ghsa_unreviewed·2026-06-21
CVE-2026-56404 [MEDIUM] CWE-190 libexpat before 2.8.2 has an integer overflow in addBinding.
libexpat before 2.8.2 has an integer overflow in addBinding.
Ubuntu
libxmltok vulnerabilities
vendor_ubuntu·2026-10-05·CVSS 6.9
CVE-2026-56404 [MEDIUM] libxmltok vulnerabilities
Title: libxmltok vulnerabilities
Summary: libxmltok could be made to crash if it opened a specially crafted
file.
It was discovered that Expat, contained with the xmltok library did not
correctly handle certain integer arithmetic. If a user or automated
system were tricked into opening a specially crafted file, an attacker
could possibly cause a denial of service. (CVE-2026-56404, CVE-2026-56405)
Instructions: In general, a standard system update will make all the necessary changes.
Ubuntu
Expat vulnerabilities
vendor_ubuntu·2026-09-21·CVSS 7.5
CVE-2026-50219 [HIGH] Expat vulnerabilities
Title: Expat vulnerabilities
Summary: Several security issues were fixed in Expat.
It was discovered that Expat could be made to allocate large amounts of
memory when parsing a small crafted document. An attacker could possibly
use this issue to cause Expat to consume resources, leading to a denial of
service. This issue was only addressed in Ubuntu 24.04 LTS.
(CVE-2025-59375)
It was discovered that Expat incorrectly handled empty external parameter
entity content. An attacker could possibly use this issue to cause Expat to
crash, resulting in a denial of service. (CVE-2026-32776)
It was discovered that Expat incorrectly handled certain DTD content. An
attacker could possibly use this issue to cause Expat to enter an infinite
loop, resulting in a denial of service. (CVE-2026-32777)
It
Red Hat
libexpat: libexpat: Arbitrary Code Execution via integer overflow in addBinding
vendor_redhat·2026-06-21·CVSS 6.9
CVE-2026-56404 [MEDIUM] CWE-190 libexpat: libexpat: Arbitrary Code Execution via integer overflow in addBinding
libexpat: libexpat: Arbitrary Code Execution via integer overflow in addBinding
libexpat before 2.8.2 has an integer overflow in addBinding.
A flaw was found in libexpat. This vulnerability, an integer overflow in the `addBinding` function, could allow a local attacker to execute arbitrary code. By exploiting this, an attacker could gain control over the affected system, compromising its confidentiality and integrity.
Statement: This Moderate impact flaw in libexpat, an XML parsing library, could lead to arbitrary code execution through an integer overflow in the `addBinding` function. Exploitation requires local access and high attack complexity, which limits its immediate risk in standard Red Hat deployments. The vulnerability primarily affects applications that process untrusted XML
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-56404 expat: libexpat: Arbitrary Code Execution via integer overflow in addBinding [fedora-all]
bugzilla·2026-07-29·CVSS 6.9
CVE-2026-56404 [MEDIUM] CVE-2026-56404 expat: libexpat: Arbitrary Code Execution via integer overflow in addBinding [fedora-all]
CVE-2026-56404 expat: libexpat: Arbitrary Code Execution via integer overflow in addBinding [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
libexpat before 2.8.2 has an integer overflow in addBinding.
Bugzilla
CVE-2026-56404 mingw-expat: libexpat: Arbitrary Code Execution via integer overflow in addBinding [fedora-all]
bugzilla·2026-07-29·CVSS 6.9
CVE-2026-56404 [MEDIUM] CVE-2026-56404 mingw-expat: libexpat: Arbitrary Code Execution via integer overflow in addBinding [fedora-all]
CVE-2026-56404 mingw-expat: libexpat: Arbitrary Code Execution via integer overflow in addBinding [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
libexpat before 2.8.2 has an integer overflow in addBinding.
Discussion:
All current releases are on mingw-expat-2.8.2.
Bugzilla
CVE-2026-56404 libexpat: libexpat: Arbitrary Code Execution via integer overflow in addBinding
bugzilla·2026-06-21·CVSS 6.9
CVE-2026-56404 [MEDIUM] CVE-2026-56404 libexpat: libexpat: Arbitrary Code Execution via integer overflow in addBinding
CVE-2026-56404 libexpat: libexpat: Arbitrary Code Execution via integer overflow in addBinding
libexpat before 2.8.2 has an integer overflow in addBinding.
2026-06-21
Published