Out-of-bounds Read Affecting kernel-zfcpdump-devel package, versions *


Severity

Recommended
medium

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.52% (43rd percentile)

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  • Snyk IDSNYK-RHEL10-KERNELZFCPDUMPDEVEL-19936298
  • published19 Sept 2026
  • disclosed11 Sept 2026

Introduced: 11 Sep 2026

NewCVE-2026-89537  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 kernel-zfcpdump-devel.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-zfcpdump-devel package and not the kernel-zfcpdump-devel package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

SUNRPC: Reject short RFC 4121 MIC tokens in gss_krb5_verify_mic_v2

gss_krb5_verify_mic_v2() reads the token ID at ptr[0..1], the flags byte at ptr[2], and padding at ptr[3..7], then passes ptr + GSS_KRB5_TOK_HDR_LEN and cksum_len to gss_krb5_mic_build_sg(). None of these accesses check read_token->len first.

The minimum safe token size is GSS_KRB5_TOK_HDR_LEN (16) plus ctx->krb5e->cksum_len (12-24, depending on the enctype). All callers accept shorter tokens from the wire:

  • gss_unwrap_resp_integ() enforces only an upper bound (offset + len <= rcv_buf->len) before allocating mic.data = kmalloc(len) and passing it to gss_verify_mic(). A malicious NFS server can therefore supply a short checksum opaque, producing a small slab allocation that the Kerberos MIC verifier reads past.

  • gss_validate() enforces only len <= RPC_MAX_AUTH_SIZE (400) before passing the wire-supplied length to gss_validate_seqno_mic(), which constructs a mic xdr_netobj and calls gss_verify_mic().

  • svcauth_gss_verify_header() enforces only checksum.len >= XDR_UNIT (4 bytes) before dispatching to gss_verify_mic().

  • svcauth_gss_unwrap_integ() checks only that the checksum fits in gsd->gsd_scratch.

Add a length guard at the top of gss_krb5_verify_mic_v2(), before any ptr[] access or scatterlist construction. Well-formed MIC tokens from gss_krb5_get_mic_v2() already have exactly GSS_KRB5_TOK_HDR_LEN + cksum_len bytes, so valid traffic is unaffected.

CVSS Base Scores

version 3.1