Affects the Linux kernel (widely deployed OS); can corrupt kernel memory and enable crashes or escalation — organization-wide impact and newsworthy.
CVE-2026-89538
Linux kernel SUNRPC krb5 v2 token parsing flaw can corrupt kernel memory.
Is CVE-2026-89538 being exploited?
Not confirmed. CVE-2026-89538 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.70% probability of exploitation in the next 30 days.
How severe is CVE-2026-89538?
CVE-2026-89538 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-89538?
Yes. A fix has been recorded for CVE-2026-89538. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-89538 affect?
CVE-2026-89538 affects Linux kernel (SUNRPC gss_krb5), Linux distributions using vulnerable kernels. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-89538?
Install vendor kernel updates or apply kernel.org patch; restrict RPC/Kerberos access until fixed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated peer can send malformed Kerberos v2 token causing kernel memory corruption, leading to crashes, privilege escalation or possible RCE.
Immediate action required
- affected>= cf4c024b908353fcc48309374d39e3399d67dfd1 and < dfcd81ab45613d45996fbf483d4ef54b0ec90ab9
- affected>= cf4c024b908353fcc48309374d39e3399d67dfd1 and < 1f9856af065b6158271687e9788407b9573fd16f
- affected>= cf4c024b908353fcc48309374d39e3399d67dfd1 and < 880effc943ed82d6811f272ed3307c222b40f4d6
- affected>= cf4c024b908353fcc48309374d39e3399d67dfd1 and < ad484748eec0a66eac0f13ab53b3fbedb7333c91
- affected3.13
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.