The python-markdown library is vulnerable to a denial of service attack (CVE-2025-69534, CVSS 7.5 HIGH) triggered by processing malformed HTML-like sequences. According to the NVD, versions up to and including 3.8 are affected; the Red Hat advisory provides the patched package version 3.5.1-6.el10_2.1 for RHEL 10. Administrators should apply the vendor-provided update to remediate the issue.
Red Hat Product Errata RHSA-2026:19155 - Security Advisory Issued: 2026-05-19 Updated: 2026-05-19 RHSA-2026:19155 - Security Advisory Overview Updated Packages Synopsis Important: python-markdown security update Type/Severity Security Advisory: Important Red Hat Lightspeed patch analysis Identify and remediate systems affected by this advisory. View affected systems Topic An update for python-markdown is now available for Red Hat Enterprise Linux 10. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section. Description Python is an interpreted, interactive, object-oriented programming language, which includes modules, classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to many system calls and libraries, as well as to various windowing systems. Security Fix(es): python-markdown: denial of service via malformed HTML-like sequences (CVE-2025-69534) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Solution For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Affected Products Red Hat Enterprise Linux for x86_64 10 x86_64 Red Hat Enterprise Linux for x86_64 - Extended Update Support 10.2 x86_64 Red Hat Enterprise Linux for IBM z Systems 10 s390x Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.2 s390x Red Hat Enterprise Linux for Power, little endian 10 ppc64le Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.2 ppc64le Red Hat Enterprise Linux for ARM 64 10 aarch64 Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.2 aarch64 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.2 aarch64 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 10.2 s390x Red Hat Enterprise Linux for Power, little endian - 4 years of support 10.2 ppc64le Red Hat Enterprise Linux for x86_64 - 4 years of updates 10.2 x86_64 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 10.2 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 10.2 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 10.2 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 10.2 s390x Fixes BZ - 2444839 - CVE-2025-69534 python-markdown: denial of service via malformed HTML-like sequences CVEs CVE-2025-69534 References https://access.redhat.com/security/updates/classification/#important Note: More recent versions of these packages may be available. 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Red Hat Enterprise Linux for x86_64 10 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b x86_64 python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for x86_64 - Extended Update Support 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b x86_64 python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for IBM z Systems 10 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b s390x python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b s390x python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for Power, little endian 10 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b ppc64le python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b ppc64le python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for ARM 64 10 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b aarch64 python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b aarch64 python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b aarch64 python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b s390x python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for Power, little endian - 4 years of support 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b ppc64le python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for x86_64 - 4 years of updates 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b x86_64 python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b x86_64 python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b aarch64 python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b ppc64le python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 10.2 SRPM python-markdown-3.5.1-6.el10_2.1.src.rpm SHA-256: 256439834c1f20a7e12819f3436dc1a60adc4a50007aaa1885cd9cfee8f7e91b s390x python3-markdown-3.5.1-6.el10_2.1.noarch.rpm SHA-256: 5c821164e4f86359127f9f84d9b56626a9cd66401ae24de18ce9dc47b4ce9465 The Red Hat security contact is secalert@redhat.com . More contact details at https://access.redhat.com/security/team/contact/ .