CVE-2026-89702nfsd: size fh_verify server sockaddr slot by xpt_locallen
- 9.8CriticalCVSS base score
- 0.50%Exploitation in 30 daysEPSS · top 56% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: size fh_verify server sockaddr slot by xpt_locallen The nfsd_fh_verify and nfsd_fh_verify_err tracepoints declare the server sockaddr slot sized by xpt_remotelen but fill it from xpt_local using xpt_locallen: TP_STRUCT__entry( ... __sockaddr(server, rqstp->rq_xprt->xpt_remotelen) ... ) TP_fast_assign( ... __assign_sockaddr(server, &rqstp->rq_xprt->xpt_local, rqstp->rq_xprt->xpt_locallen); ... ) When xpt_locallen exceeds xpt_remotelen, __assign_sockaddr's memcpy writes past the reserved ring-buffer slot. In the reverse direction (xpt_locallen < xpt_remotelen) the slot is oversized and the unwritten tail leaks prior ring-buffer contents to trace consumers. The write-past-end case is reachable on NFS/UDP. svc_xprt_set_remote() is only called from svc_tcp_accept() (net/sunrpc/svcsock.c) and from the RDMA connect path; svc_create_socket() for UDP calls only svc_xprt_set_local(), so xpt_remotelen stays 0 for the xprt's lifetime. Every fh_verify trace for an NFSv2/v3-over-UDP request then copies 16 or 28 bytes from xpt_local into a zero-byte slot. The other NFSD tracepoints that record the server address (NFSD_TRACE_PROC_CALL_FIELDS, NFSD_TRACE_PROC_RES_FIELDS, SVC_RQST_ENDPOINT_FIELDS) already size the server slot by xpt_locallen; nfsd_fh_verify and nfsd_fh_verify_err were the only exceptions. Fix by sizing the server slot with xpt_locallen so the declared slot matches the copy length. The client slot and its assignment already agree on xpt_remotelen and are left untouched.
Timeline
ID reserved
By Linux
Published
- 49 days later
· 49 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.50% · top 56% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected dcbebc86850324fbe0a993ce352f0539cd98038a – < 4c7569ad68fc8b86ca40c7e56ef21460c0344955
- affected 051382885552e12541cc0ebf82092be374a9ed2a – < 50d9d581d2af80799125ee62617d37e9b6b476a7
- affected 051382885552e12541cc0ebf82092be374a9ed2a – < 1c6a4d6c20fd42552ffc2c3dfaed2139c9477ee5
- affected 051382885552e12541cc0ebf82092be374a9ed2a – < 95d064f9828a20ccca5ae90a17be3e2076f25272
- affected 051382885552e12541cc0ebf82092be374a9ed2a – < 7ff8d6363cffff45654ea85e319f7c0c54226012
- affected 051382885552e12541cc0ebf82092be374a9ed2a – < 719a10e3f5f868c3c4ac3cf3648c5775d12034bd
- affected 051382885552e12541cc0ebf82092be374a9ed2a – < 71d068490098b1d23c63b2345e40675d3a1ca763
- affected 62980365d6e894234b29f44fb2bfad4f7f8bb824
- affected 5.15.154 – < 5.15.224
- affected 6.0
- unaffected < 6.0
- unaffected 5.15.224 – ≤ 5.15.*
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.109 – ≤ 6.12.*
- unaffected 6.18.50 – ≤ 6.18.*
- unaffected 7.2.4 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References7
- https://git.kernel.org/stable/c/4c7569ad68fc8b86ca40c7e56ef21460c0344955 (opens in a new tab)
- https://git.kernel.org/stable/c/50d9d581d2af80799125ee62617d37e9b6b476a7 (opens in a new tab)
- https://git.kernel.org/stable/c/1c6a4d6c20fd42552ffc2c3dfaed2139c9477ee5 (opens in a new tab)
- https://git.kernel.org/stable/c/95d064f9828a20ccca5ae90a17be3e2076f25272 (opens in a new tab)
- https://git.kernel.org/stable/c/7ff8d6363cffff45654ea85e319f7c0c54226012 (opens in a new tab)
- https://git.kernel.org/stable/c/719a10e3f5f868c3c4ac3cf3648c5775d12034bd (opens in a new tab)
- https://git.kernel.org/stable/c/71d068490098b1d23c63b2345e40675d3a1ca763 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-76614 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-89702)Record last updated .