Critical severity · published Sep 24, 2026
CVE-2026-93207
SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry
9.8
CVSS
0.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
b0bc53470d1af01f62a0fe2d405cf56477804863 before 56b29d62017c7dd1718d060dd5b3a2ce61095d0c; b0bc53470d1af01f62a0fe2d405cf56477804863 before 0e18641708eaa8bc3c1ff338cd844aeadbd52bac; b0bc53470d1af01f62a0fe2d405cf56477804863 before e0778464049b0238f2915a40007a4154f86cf351; b0bc53470d1af01f62a0fe2d405cf56477804863 before 0fa8a8acae57e6373962741d5b06d13f44aba6a9; b0bc53470d1af01f62a0fe2d405cf56477804863 before 11539e8fcce0b0af062ae5fecf7b3676c2f7aeed; 6.3 · source: vendor