CVE Catalog

CVE-2026-93207

CriticalCVSS 9.8
Published: Updated: Translated: NVD NIST

Summary

A vulnerability in the Linux kernel's SUNRPC module involves not zeroing the rpc_gss_wire_cred structure at the entry of svcauth_gss_decode_credbody(). Since the structure is reused across requests, early decode failures leave partially stale data, potentially leading to dangling pointers or incorrect lengths. The fix zeroes the structure at entry.

Risk Assessment

The risk includes the potential use of corrupted GSS authentication data, possibly leading to session integrity issues or server crashes. This may affect the security of RPC communication.

Recommendation

Apply a kernel update that includes the fix zeroing the rpc_gss_wire_cred structure at function entry. Also check system logs for GSS-related errors.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry svcauth_gss_decode_credbody() writes the caller's rpc_gss_wire_cred field by field and assigns gc_ctx.len only on the success tail. The caller storage is svcdata->clcred, which lives in the per-svc_rqst gss_svc_data and is reused across requests. Early decode failures leave partially decoded state mixed with residue from the prior request. The trailing body_len tightness check is the sharpest case: xdr_stream_decode_opaque_inline() has already written gc_ctx.data with a borrowed inline pointer into the current request's XDR pages, but gc_ctx.len retains its prior value. Once the request pages are released the pooled clcred carries a dangling pointer paired with a stale length. Zero the caller's rpc_gss_wire_cred at function entry so that every early-return path leaves a deterministic all-zero cred. On the trailing tightness-check path, gc_ctx.len is now zero instead of stale, which neuters length-driven consumers such as gss_svc_searchbyctx() that would otherwise walk the dangling data pointer.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS