CVE-2025-6021 | Libxml2: integer overflow in xmlbuildqname() leads to stack buffer overflow in libxml2

Exp

A flaw was found in libxml2's xmlBuildQName function, where integer overflows in buffer size calculations can lead to a stack-based buffer overflow. This issue can result in memory corruption or a denial of service when processing crafted input.

Published: 2025-06-12 Last update: 2026-05-12 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-6021 is rated High Exploit Risk (65/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.07%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2025-6021

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2025-6021

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 2.12% 1.07% -1.05%
2 2026-04-22 1.73% 2.12% +0.38%
3 2026-04-21 1.73%

Full EPSS history (33 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-6021

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-6021

GitHub Security Advisory for CVE-2025-6021

GHSA-32vr-5hxf-x93f · Severity: high — A flaw was found in libxml2's xmlBuildQName function, where integer overflows in buffer size...

OS Trackers for CVE-2025-6021

vendor priority summary link
alpine CVE-2025-6021: 2 source package rows (libxml2, qt6-qtwebengine); 129 state rows across 8 repos (3.19-main, 3.20-main, 3.21-main, 3.22-community, 3.22-main, 3.23-main, edge-community, edge-main); fixed 7, open 122. https://security.alpinelinux.org/vuln/CVE-2025-6021
debian not yet assigned CVE-2025-6021 not yet assigned priority: Debian including 1 source packages (libxml2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-6021
redhat medium https://access.redhat.com/security/cve/CVE-2025-6021
suse high CVE-2025-6021 severity important: SUSE including 364 source package names (0.23.1-11.20:libxml2-2-2.10.3-150500.5.29.1, 0.3.2-1.2:libxml2-2-2.10.3-150500.5.29.1, …), 1223 product×package rows across 385 product lines (Container bci/kiwi, Container bci/spack, … (385 product lines)): Fixed 769, Known Not Affected 233, Known Affected 221. https://www.suse.com/security/cve/CVE-2025-6021/
ubuntu medium CVE-2025-6021 medium priority: Ubuntu including 1 source packages (libxml2), 9 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, trusty, upstream, xenial): released 8, ignored 1. https://ubuntu.com/security/CVE-2025-6021

Affected software / configurations for CVE-2025-6021

Vendor Product Version Raw CPE
xmlsoft libxml2 < 2.14.4 cpe:2.3:a:xmlsoft:libxml2:*:*:*:*:*:*:*:*
redhat jboss_core_services cpe:2.3:a:redhat:jboss_core_services:-:*:*:*:*:*:*:*
redhat openshift_container_platform 4.12 cpe:2.3:a:redhat:openshift_container_platform:4.12:*:*:*:*:*:*:*
redhat openshift_container_platform 4.13 cpe:2.3:a:redhat:openshift_container_platform:4.13:*:*:*:*:*:*:*
redhat openshift_container_platform 4.14 cpe:2.3:a:redhat:openshift_container_platform:4.14:*:*:*:*:*:*:*
redhat openshift_container_platform 4.15 cpe:2.3:a:redhat:openshift_container_platform:4.15:*:*:*:*:*:*:*
redhat openshift_container_platform 4.16 cpe:2.3:a:redhat:openshift_container_platform:4.16:*:*:*:*:*:*:*
redhat openshift_container_platform 4.17 cpe:2.3:a:redhat:openshift_container_platform:4.17:*:*:*:*:*:*:*
redhat openshift_container_platform 4.18 cpe:2.3:a:redhat:openshift_container_platform:4.18:*:*:*:*:*:*:*
redhat openshift_container_platform_for_arm64 4.13 cpe:2.3:a:redhat:openshift_container_platform_for_arm64:4.13:*:*:*:*:*:*:*
redhat openshift_container_platform_for_arm64 4.14 cpe:2.3:a:redhat:openshift_container_platform_for_arm64:4.14:*:*:*:*:*:*:*
redhat openshift_container_platform_for_arm64 4.15 cpe:2.3:a:redhat:openshift_container_platform_for_arm64:4.15:*:*:*:*:*:*:*
redhat openshift_container_platform_for_arm64 4.16 cpe:2.3:a:redhat:openshift_container_platform_for_arm64:4.16:*:*:*:*:*:*:*
redhat openshift_container_platform_for_arm64 4.17 cpe:2.3:a:redhat:openshift_container_platform_for_arm64:4.17:*:*:*:*:*:*:*
redhat openshift_container_platform_for_arm64 4.18 cpe:2.3:a:redhat:openshift_container_platform_for_arm64:4.18:*:*:*:*:*:*:*
redhat openshift_container_platform_for_ibm_z 4.13 cpe:2.3:a:redhat:openshift_container_platform_for_ibm_z:4.13:*:*:*:*:*:*:*
redhat openshift_container_platform_for_ibm_z 4.14 cpe:2.3:a:redhat:openshift_container_platform_for_ibm_z:4.14:*:*:*:*:*:*:*
redhat openshift_container_platform_for_ibm_z 4.15 cpe:2.3:a:redhat:openshift_container_platform_for_ibm_z:4.15:*:*:*:*:*:*:*
redhat openshift_container_platform_for_ibm_z 4.16 cpe:2.3:a:redhat:openshift_container_platform_for_ibm_z:4.16:*:*:*:*:*:*:*
redhat openshift_container_platform_for_ibm_z 4.17 cpe:2.3:a:redhat:openshift_container_platform_for_ibm_z:4.17:*:*:*:*:*:*:*
redhat openshift_container_platform_for_ibm_z 4.18 cpe:2.3:a:redhat:openshift_container_platform_for_ibm_z:4.18:*:*:*:*:*:*:*
redhat openshift_container_platform_for_linuxone 4.13 cpe:2.3:a:redhat:openshift_container_platform_for_linuxone:4.13:*:*:*:*:*:*:*
redhat openshift_container_platform_for_linuxone 4.14 cpe:2.3:a:redhat:openshift_container_platform_for_linuxone:4.14:*:*:*:*:*:*:*
redhat openshift_container_platform_for_linuxone 4.15 cpe:2.3:a:redhat:openshift_container_platform_for_linuxone:4.15:*:*:*:*:*:*:*
redhat openshift_container_platform_for_linuxone 4.16 cpe:2.3:a:redhat:openshift_container_platform_for_linuxone:4.16:*:*:*:*:*:*:*
redhat openshift_container_platform_for_linuxone 4.17 cpe:2.3:a:redhat:openshift_container_platform_for_linuxone:4.17:*:*:*:*:*:*:*
redhat openshift_container_platform_for_linuxone 4.18 cpe:2.3:a:redhat:openshift_container_platform_for_linuxone:4.18:*:*:*:*:*:*:*
redhat openshift_container_platform_for_power 4.13 cpe:2.3:a:redhat:openshift_container_platform_for_power:4.13:*:*:*:*:*:*:*
redhat openshift_container_platform_for_power 4.14 cpe:2.3:a:redhat:openshift_container_platform_for_power:4.14:*:*:*:*:*:*:*
redhat openshift_container_platform_for_power 4.15 cpe:2.3:a:redhat:openshift_container_platform_for_power:4.15:*:*:*:*:*:*:*
redhat openshift_container_platform_for_power 4.16 cpe:2.3:a:redhat:openshift_container_platform_for_power:4.16:*:*:*:*:*:*:*
redhat openshift_container_platform_for_power 4.17 cpe:2.3:a:redhat:openshift_container_platform_for_power:4.17:*:*:*:*:*:*:*
redhat openshift_container_platform_for_power 4.18 cpe:2.3:a:redhat:openshift_container_platform_for_power:4.18:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 9.0 cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
redhat enterprise_linux 10.0 cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*
redhat enterprise_linux_eus 8.4 cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:*
redhat enterprise_linux_eus 8.6 cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_eus 8.8 cpe:2.3:o:redhat:enterprise_linux_eus:8.8:*:*:*:*:*:*:*
redhat enterprise_linux_eus 9.4 cpe:2.3:o:redhat:enterprise_linux_eus:9.4:*:*:*:*:*:*:*
redhat enterprise_linux_eus 9.6 cpe:2.3:o:redhat:enterprise_linux_eus:9.6:*:*:*:*:*:*:*
redhat enterprise_linux_eus 10.0 cpe:2.3:o:redhat:enterprise_linux_eus:10.0:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64 8.0_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64:8.0_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64 9.0_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64:9.0_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64 9.4_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64:9.4_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64 10.0_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64:10.0_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64_eus 9.4_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:9.4_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64_eus 9.6_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:9.6_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64_eus 10.0_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:10.0_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems 8.0_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems 9.4_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:9.4_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems 10.0_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:10.0_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems_eus 9.0_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:9.0_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems_eus 9.4_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:9.4_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems_eus 9.6_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:9.6_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems_eus 10.0_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:10.0_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian 8.0_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian 9.0_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:9.0_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian 10.0_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:10.0_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 9.4_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:9.4_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 9.6_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:9.6_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 10.0_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:10.0_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 8.2 cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 8.4 cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 8.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 9.2 cpe:2.3:o:redhat:enterprise_linux_server_aus:9.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 9.4 cpe:2.3:o:redhat:enterprise_linux_server_aus:9.4:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 9.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:9.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 9.4_ppc64le cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:9.4_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 8.8 cpe:2.3:o:redhat:enterprise_linux_server_tus:8.8:*:*:*:*:*:*:*
redhat in-vehicle_operating_system 1.0 cpe:2.3:o:redhat:in-vehicle_operating_system:1.0:*:*:*:*:*:*:*

References for CVE-2025-6021

URL Tags
https://access.redhat.com/errata/RHSA-2025:10630 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:10698 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:10699 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:11580 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:11673
https://access.redhat.com/errata/RHSA-2025:12098 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:12099 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:12199 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:12237 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:12239 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:12240 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:12241 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:13267 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:13289 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:13325 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:13335 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:13336 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:14059 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:14396 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:15308 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:15672 Third Party Advisory
https://access.redhat.com/errata/RHSA-2025:19020
https://access.redhat.com/errata/RHSA-2026:7519
https://access.redhat.com/security/cve/CVE-2025-6021 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2372406 Issue Tracking
https://gitlab.gnome.org/GNOME/libxml2/-/issues/926 Exploit Issue Tracking Vendor Advisory
https://lists.debian.org/debian-lts-announce/2025/07/msg00014.html
https://cert-portal.siemens.com/productcert/html/ssa-032379.html
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