# CVE-2025-3576: Krb5: kerberos rc4-hmac-md5 checksum vulnerability enabling message spoofing via md5 collisions > Attackers can spoof GSSAPI messages via MD5 collisions if RC4-HMAC-MD5 is preferred, enabling unauthorized tampering in Red Hat Enterprise Linux environments. - **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 15 Apr 2025 - **Updated:** 1 Sep 2026 - **Also known as:** ALSA-2025:8411, ALSA-2025:9418, ALSA-2025:9430, AZL-60928, CLSA-2025-1751892444, CLSA-2025-1751895517, CLSA-2025-1755113592, CLSA-2025-1755603427, DEBIAN-CVE-2025-3576, DLA-4195-1, ECHO-64ee-f30c-7bc0, GHSA-rfh5-gx7w-h7v7, OESA-2025-2124, OESA-2025-2125, OESA-2025-2126, RHSA-2025:13664, RHSA-2025:13777, RHSA-2025:15000, RHSA-2025:15001, RHSA-2025:15002, RHSA-2025:15003, RHSA-2025:15004, RHSA-2025:8411, RHSA-2025:9418, RHSA-2025:9430, RLSA-2025:8411, RLSA-2025:9418, RLSA-2025:9430, SUSE-SU-2025:03227-1, SUSE-SU-2025:03270-1, SUSE-SU-2025:20719-1, SUSE-SU-2025:3698-1, SUSE-SU-2025:3699-1, SUSE-SU-2025:3729-1, UBUNTU-CVE-2025-3576, USN-7542-1 ## What is CVE-2025-3576? CVE-2025-3576 is a medium-severity vulnerability in Red Hat Discovery 2, published on 15 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A vulnerability in the MIT Kerberos implementation allows GSSAPI-protected messages using RC4-HMAC-MD5 to be spoofed due to weaknesses in the MD5 checksum design. If RC4 is preferred over stronger encryption types, an attacker could exploit MD5 collisions to forge message integrity codes. This may lead to unauthorized message tampering. Weakness: CWE-328 (Use of Weak Hash) ## Which versions are affected by CVE-2025-3576? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `krb5-devel` | AlmaLinux:10 | All versions | 1.21.3-8.el10_0 | | `krb5-libs` | AlmaLinux:10 | All versions | 1.21.3-8.el10_0 | | `krb5-pkinit` | AlmaLinux:10 | All versions | 1.21.3-8.el10_0 | | `krb5-server` | AlmaLinux:10 | All versions | 1.21.3-8.el10_0 | | `krb5-server-ldap` | AlmaLinux:10 | All versions | 1.21.3-8.el10_0 | | `krb5-workstation` | AlmaLinux:10 | All versions | 1.21.3-8.el10_0 | | `libkadm5` | AlmaLinux:10 | All versions | 1.21.3-8.el10_0 | | `krb5-devel` | AlmaLinux:8 | All versions | 1.18.2-32.el8_10 | | `krb5-libs` | AlmaLinux:8 | All versions | 1.18.2-32.el8_10 | | `krb5-pkinit` | AlmaLinux:8 | All versions | 1.18.2-32.el8_10 | | `krb5-server` | AlmaLinux:8 | All versions | 1.18.2-32.el8_10 | | `krb5-server-ldap` | AlmaLinux:8 | All versions | 1.18.2-32.el8_10 | | `krb5-workstation` | AlmaLinux:8 | All versions | 1.18.2-32.el8_10 | | `libkadm5` | AlmaLinux:8 | All versions | 1.18.2-32.el8_10 | | `krb5-devel` | AlmaLinux:9 | All versions | 1.21.1-8.el9_6 | | `krb5-libs` | AlmaLinux:9 | All versions | 1.21.1-8.el9_6 | | `krb5-pkinit` | AlmaLinux:9 | All versions | 1.21.1-8.el9_6 | | `krb5-server` | AlmaLinux:9 | All versions | 1.21.1-8.el9_6 | | `krb5-server-ldap` | AlmaLinux:9 | All versions | 1.21.1-8.el9_6 | | `krb5-workstation` | AlmaLinux:9 | All versions | 1.21.1-8.el9_6 | | `libkadm5` | AlmaLinux:9 | All versions | 1.21.1-8.el9_6 | | `krb5` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-debuginfo` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-debugsource` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-devel` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-libs` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-libs-debuginfo` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-pkinit` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-pkinit-debuginfo` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-server` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-server-debuginfo` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-server-ldap` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-server-ldap-debuginfo` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-workstation` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5-workstation-debuginfo` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `libkadm5` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `libkadm5-debuginfo` | Red Hat:enterprise_linux:10.0 | All versions | 0:1.21.3-8.el10_0 | | `krb5` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.18.2-32.el8_10 | | `krb5-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.18.2-32.el8_10 | | `krb5-debugsource` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.18.2-32.el8_10 | ## How do I fix CVE-2025-3576? Apply the vendor's patch. ## Is CVE-2025-3576 being exploited? There is no known exploitation of CVE-2025-3576 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-3576 and fix it if it is affected. What it is: CVE-2025-3576 is a medium-severity vulnerability in Red Hat Discovery 2, published on 15 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2025-3576 in the wild and no public exploit code. Affected product: Red Hat Discovery 2. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-3576/ (Markdown: https://insights.sbomify.com/CVE-2025-3576/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-3576 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-3576 - OSV: https://osv.dev/vulnerability/CVE-2025-3576 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-3576/ Summaries are generated and may contain mistakes; the official description above is the record.