Krb5: kerberos rc4-hmac-md5 checksum vulnerability enabling message spoofing via md5 collisions
Priority LOW 26CWE-328Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Partial Red Hat: 20 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00351 28th percentileScored 2026-11-07
Fix Partial krb5: 1.22Red Hat: 11 advisoriesRed Hat: 20 fixed, 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | krb5 | before 1.22 | 1.22 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 10 | — | 1.21.3-8.el10_0 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | 1.18.2-32.el8_10 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.2 Advanced Update Support | — | 1.17-19.el8_2.3 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | — | 1.18.2-9.el8_4.3 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | — | 1.18.2-9.el8_4.3 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | — | 1.18.2-16.el8_6.4 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.6 Telecommunications Update Service | — | 1.18.2-16.el8_6.4 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions | — | 1.18.2-16.el8_6.4 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | — | 1.18.2-26.el8_8.5 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | — | 1.18.2-26.el8_8.5 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 1.21.1-8.el9_6 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 1.21.1-8.el9_6 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions | — | 1.19.1-16.el9_0.4 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | — | 1.20.1-9.el9_2.3 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.4 Extended Update Support | — | 1.21.1-2.el9_4.2 | Patch available | CNA |
| Red Hat | Red Hat Discovery 2 | — | 2.0.0-1752592913 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
- krb5 Vendor— Affected before 1.22 Fixed in 1.22 Patch available CNA
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in 1.21.3-8.el10_0 Patch available CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 1.18.2-32.el8_10 Patch available CNA
- Red Hat Enterprise Linux 8.2 Advanced Update Support VendorRed Hat Affected — Fixed in 1.17-19.el8_2.3 Patch available CNA
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support VendorRed Hat Affected — Fixed in 1.18.2-9.el8_4.3 Patch available CNA
- Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On VendorRed Hat Affected — Fixed in 1.18.2-9.el8_4.3 Patch available CNA
- Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support VendorRed Hat Affected — Fixed in 1.18.2-16.el8_6.4 Patch available CNA
- Red Hat Enterprise Linux 8.6 Telecommunications Update Service VendorRed Hat Affected — Fixed in 1.18.2-16.el8_6.4 Patch available CNA
- Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 1.18.2-16.el8_6.4 Patch available CNA
- Red Hat Enterprise Linux 8.8 Telecommunications Update Service VendorRed Hat Affected — Fixed in 1.18.2-26.el8_8.5 Patch available CNA
- Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 1.18.2-26.el8_8.5 Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 1.21.1-8.el9_6 Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 1.21.1-8.el9_6 Patch available CNA
- Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 1.19.1-16.el9_0.4 Patch available CNA
- Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 1.20.1-9.el9_2.3 Patch available CNA
- Red Hat Enterprise Linux 9.4 Extended Update Support VendorRed Hat Affected — Fixed in 1.21.1-2.el9_4.2 Patch available CNA
- Red Hat Discovery 2 VendorRed Hat Affected — Fixed in 2.0.0-1752592913 Patch available CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE names CNA · 22
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/o:redhat:enterprise_linux:10.0 | 10.0 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:8::baseos | 8 | — | Red Hat |
| cpe:/o:redhat:rhel_aus:8.2::baseos | 8.2 | — | Red Hat |
| cpe:/o:redhat:rhel_aus:8.4::baseos | 8.4 | — | Red Hat |
| cpe:/o:redhat:rhel_eus_long_life:8.4::baseos | 8.4 | — | Red Hat |
| cpe:/o:redhat:rhel_aus:8.6::baseos | 8.6 | — | Red Hat |
| cpe:/o:redhat:rhel_e4s:8.6::baseos | 8.6 | — | Red Hat |
| cpe:/o:redhat:rhel_tus:8.6::baseos | 8.6 | — | Red Hat |
| cpe:/o:redhat:rhel_e4s:8.8::baseos | 8.8 | — | Red Hat |
| cpe:/o:redhat:rhel_tus:8.8::baseos | 8.8 | — | Red Hat |
- cpe:/o:redhat:enterprise_linux:10.0 Versions 10.0 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:8::baseos Versions 8 — ·Red Hat
- cpe:/o:redhat:rhel_aus:8.2::baseos Versions 8.2 — ·Red Hat
- cpe:/o:redhat:rhel_aus:8.4::baseos Versions 8.4 — ·Red Hat
- cpe:/o:redhat:rhel_eus_long_life:8.4::baseos Versions 8.4 — ·Red Hat
- cpe:/o:redhat:rhel_aus:8.6::baseos Versions 8.6 — ·Red Hat
- cpe:/o:redhat:rhel_e4s:8.6::baseos Versions 8.6 — ·Red Hat
- cpe:/o:redhat:rhel_tus:8.6::baseos Versions 8.6 — ·Red Hat
- cpe:/o:redhat:rhel_e4s:8.8::baseos Versions 8.8 — ·Red Hat
- cpe:/o:redhat:rhel_tus:8.8::baseos Versions 8.8 — ·Red Hat
Show 12 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/a:redhat:enterprise_linux:9::appstream | 9 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:9::baseos | 9 | — | Red Hat |
| cpe:/a:redhat:rhel_e4s:9.0::appstream | 9.0 | — | Red Hat |
| cpe:/o:redhat:rhel_e4s:9.0::baseos | 9.0 | — | Red Hat |
| cpe:/a:redhat:rhel_e4s:9.2::appstream | 9.2 | — | Red Hat |
| cpe:/o:redhat:rhel_e4s:9.2::baseos | 9.2 | — | Red Hat |
| cpe:/a:redhat:rhel_eus:9.4::appstream | 9.4 | — | Red Hat |
| cpe:/o:redhat:rhel_eus:9.4::baseos | 9.4 | — | Red Hat |
| cpe:/a:redhat:discovery:2::el9 | 2 | — | Red Hat |
| cpe:/o:redhat:rhel_els:6 | 6 | — | Red Hat |
| cpe:/o:redhat:rhel_els:7 | 7 | — | Red Hat |
| cpe:/a:redhat:openshift:4 | 4 | — | Red Hat |
- cpe:/a:redhat:enterprise_linux:9::appstream Versions 9 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:9::baseos Versions 9 — ·Red Hat
- cpe:/a:redhat:rhel_e4s:9.0::appstream Versions 9.0 — ·Red Hat
- cpe:/o:redhat:rhel_e4s:9.0::baseos Versions 9.0 — ·Red Hat
- cpe:/a:redhat:rhel_e4s:9.2::appstream Versions 9.2 — ·Red Hat
- cpe:/o:redhat:rhel_e4s:9.2::baseos Versions 9.2 — ·Red Hat
- cpe:/a:redhat:rhel_eus:9.4::appstream Versions 9.4 — ·Red Hat
- cpe:/o:redhat:rhel_eus:9.4::baseos Versions 9.4 — ·Red Hat
- cpe:/a:redhat:discovery:2::el9 Versions 2 — ·Red Hat
- cpe:/o:redhat:rhel_els:6 Versions 6 — ·Red Hat
- cpe:/o:redhat:rhel_els:7 Versions 7 — ·Red Hat
- cpe:/a:redhat:openshift:4 Versions 4 — ·Red Hat
Remediation
- Fix · CNA krb5 Fixed in 1.22
Red Hat 11 advisories
- RHSA-2025:15001 Released 2025-09-02 · Red Hat rating Moderatekrb5 security update
- Red Hat Enterprise Linux BaseOS AUS (v.8.6) krb5-1.18.2-16.el8_6.4, krb5-devel-1.18.2-16.el8_6.4, krb5-libs-1.18.2-16.el8_6.4 +5
- Red Hat Enterprise Linux BaseOS E4S (v.8.6) krb5-1.18.2-16.el8_6.4, krb5-devel-1.18.2-16.el8_6.4, krb5-libs-1.18.2-16.el8_6.4 +5
- Red Hat Enterprise Linux BaseOS TUS (v.8.6) krb5-1.18.2-16.el8_6.4, krb5-devel-1.18.2-16.el8_6.4, krb5-libs-1.18.2-16.el8_6.4 +5
- RHSA-2025:15004 Released 2025-09-02 · Red Hat rating Moderatekrb5 security update
- Red Hat Enterprise Linux BaseOS E4S (v.8.8) krb5-1.18.2-26.el8_8.5, krb5-devel-1.18.2-26.el8_8.5, krb5-libs-1.18.2-26.el8_8.5 +5
- Red Hat Enterprise Linux BaseOS TUS (v.8.8) krb5-1.18.2-26.el8_8.5, krb5-devel-1.18.2-26.el8_8.5, krb5-libs-1.18.2-26.el8_8.5 +5
- RHSA-2025:15000 Released 2025-09-02 · Red Hat rating Moderatekrb5 security update
- Red Hat Enterprise Linux AppStream E4S (v.9.0) krb5-devel-1.19.1-16.el9_0.4
- Red Hat Enterprise Linux BaseOS E4S (v.9.0) krb5-1.19.1-16.el9_0.4, krb5-libs-1.19.1-16.el9_0.4, krb5-pkinit-1.19.1-16.el9_0.4 +4
Show 8 more Red Hat advisories
- RHSA-2025:15002 Released 2025-09-02 · Red Hat rating Moderatekrb5 security update
- Red Hat Enterprise Linux BaseOS AUS (v. 8.2) krb5-1.17-19.el8_2.3, krb5-devel-1.17-19.el8_2.3, krb5-libs-1.17-19.el8_2.3 +5
- RHSA-2025:15003 Released 2025-09-02 · Red Hat rating Moderatekrb5 security update
- Red Hat Enterprise Linux BaseOS AUS (v.8.4) krb5-1.18.2-9.el8_4.3, krb5-devel-1.18.2-9.el8_4.3, krb5-libs-1.18.2-9.el8_4.3 +5
- Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) krb5-1.18.2-9.el8_4.3, krb5-devel-1.18.2-9.el8_4.3, krb5-libs-1.18.2-9.el8_4.3 +5
- RHSA-2025:13777 Released 2025-08-13 · Red Hat rating Moderatekrb5 security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) krb5-devel-1.20.1-9.el9_2.3
- Red Hat Enterprise Linux BaseOS E4S (v.9.2) krb5-1.20.1-9.el9_2.3, krb5-libs-1.20.1-9.el9_2.3, krb5-pkinit-1.20.1-9.el9_2.3 +4
- RHSA-2025:13664 Released 2025-08-12 · Red Hat rating Moderatekrb5 security update
- Red Hat Enterprise Linux AppStream EUS (v.9.4) krb5-devel-1.21.1-2.el9_4.2
- Red Hat Enterprise Linux BaseOS EUS (v.9.4) krb5-1.21.1-2.el9_4.2, krb5-libs-1.21.1-2.el9_4.2, krb5-pkinit-1.21.1-2.el9_4.2 +4
- RHSA-2025:11487 Released 2025-07-21 · Red Hat rating ImportantA Subscription Management tool for finding and reporting Red Hat product usage
- Red Hat Discovery 2 registry.redhat.io/discovery/discovery-server-rhel9
- RHSA-2025:9430 Released 2025-06-24 · Red Hat rating Moderatekrb5 security update
- Red Hat Enterprise Linux AppStream (v. 9) krb5-devel-1.21.1-8.el9_6
- Red Hat Enterprise Linux BaseOS (v. 9) krb5-1.21.1-8.el9_6, krb5-libs-1.21.1-8.el9_6, krb5-pkinit-1.21.1-8.el9_6 +4
- RHSA-2025:9418 Released 2025-06-24 · Red Hat rating Moderatekrb5 security update
- Red Hat Enterprise Linux AppStream (v. 10) krb5-devel-1.21.3-8.el10_0
- Red Hat Enterprise Linux BaseOS (v. 10) krb5-1.21.3-8.el10_0, krb5-libs-1.21.3-8.el10_0, krb5-pkinit-1.21.3-8.el10_0 +4
- RHSA-2025:8411 Released 2025-06-03 · Red Hat rating Moderatekrb5 security update
- Red Hat Enterprise Linux BaseOS (v. 8) krb5-1.18.2-32.el8_10, krb5-devel-1.18.2-32.el8_10, krb5-libs-1.18.2-32.el8_10 +5
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat Discovery 2 | Fixed | RHSA-2025:11487 |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2025:9418 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:9430 |
| Red Hat Enterprise Linux AppStream E4S (v.9.0) | Fixed | RHSA-2025:15000 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2025:13777 |
| Red Hat Enterprise Linux AppStream EUS (v.9.4) | Fixed | RHSA-2025:13664 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2025:9418 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2025:8411 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2025:9430 |
| Red Hat Enterprise Linux BaseOS AUS (v. 8.2) | Fixed | RHSA-2025:15002 |
| Red Hat Enterprise Linux BaseOS AUS (v.8.4) | Fixed | RHSA-2025:15003 |
| Red Hat Enterprise Linux BaseOS AUS (v.8.6) | Fixed | RHSA-2025:15001 |
| Red Hat Enterprise Linux BaseOS E4S (v.8.6) | Fixed | RHSA-2025:15001 |
| Red Hat Enterprise Linux BaseOS E4S (v.8.8) | Fixed | RHSA-2025:15004 |
| Red Hat Enterprise Linux BaseOS E4S (v.9.0) | Fixed | RHSA-2025:15000 |
| Red Hat Enterprise Linux BaseOS E4S (v.9.2) | Fixed | RHSA-2025:13777 |
| Red Hat Enterprise Linux BaseOS EUS (v.9.4) | Fixed | RHSA-2025:13664 |
| Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) | Fixed | RHSA-2025:15003 |
| Red Hat Enterprise Linux BaseOS TUS (v.8.6) | Fixed | RHSA-2025:15001 |
| Red Hat Enterprise Linux BaseOS TUS (v.8.8) | Fixed | RHSA-2025:15004 |
Not affected: 1 product
- Red Hat Discovery 2
Timeline
- 2026-10-02 Threatist record created from CVE-2025-3576
- 2026-10-03 Alias added: GHSA-rfh5-gx7w-h7v7
References
More Red Hat vulnerabilities
- TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
- TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
- TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
- TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
- TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2025-3576 · CVE Program
- CVE-2025-3576 · NVD
- FIRST EPSS
- GHSA-rfh5-gx7w-h7v7 · GitHub Advisory Database · CC BY 4.0
- CVE-2025-3576 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences