CVE-2026-89538: In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Reject krb5 v2 wrap tokens with oversized e
Summary
A vulnerability in the Linux kernel's SUNRPC (Sun Remote Procedure Call, a network communication system) layer allows malformed Kerberos v2 tokens (encrypted security credentials) with oversized 'ec' fields to leave buffer data structures in an invalid state. The fix rejects these malformed tokens before processing them, ensuring the system returns a clear error instead of leaving data structures inconsistent.
Solution / Mitigation
Reject oversized ec field tokens before calling xdr_buf_trim(). Compare the trim length against the remaining wrapped segment (buf->len - offset) rather than the whole buffer, and return a GSS_S_DEFECTIVE_TOKEN error for structurally malformed tokens per RFC 4121.
Vulnerability Details
EPSS: 0.0%
September 11, 2026
Classification
Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-89538
First tracked: September 11, 2026 at 08:07 PM
Classified by LLM (prompt v3) · confidence: 95%