Answer in brief
CVE-2026-89674 records a Critical severity (CVSS 9.8) vulnerability in nfsd: fix XDR length calculation in nfsd4_ff_encode_layoutget. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=9b9960a0ca4773e21c4b153ed355583946346b25 <e7d9d23ecd9172f05b09bb678ff22db8e361c428 || >=9b9960a0ca4773e21c4b153ed355583946346b25 <0380129b1373c437eb35401a174671c8888f4b80 || >=9b9960a0ca4773e21c4b153ed355583946346b25 <c81cef6a805dec266c10fc4f83c93d6fcf1a2b43 || >=9b9960a0ca4773e21c4b153ed355583946346b25 <f9868174af49d207fbaf0c5e055d088a983684af | e7d9d23ecd9172f05b09bb678ff22db8e361c428, 0380129b1373c437eb35401a174671c8888f4b80, c81cef6a805dec266c10fc4f83c93d6fcf1a2b43, f9868174af49d207fbaf0c5e055d088a983684af |
| Linux/Linuxgeneric | 4.8 | Not reported |
| Linux/Linuxgeneric | >=9b9960a0ca4773e21c4b153ed355583946346b25 <3a7fd224df0fbb42167eb1b77be45d72fe0b1098 || >=9b9960a0ca4773e21c4b153ed355583946346b25 <29e4478e2ed5a227e8f0c33cacb91bf227cedd47 || >=9b9960a0ca4773e21c4b153ed355583946346b25 <65a72b721943618eeb3a41c8b36e915591f3f83f || >=9b9960a0ca4773e21c4b153ed355583946346b25 <bee826c00ac900473f91306f1f3e5a5a81fd4a74 || >=9b9960a0ca4773e21c4b153ed355583946346b25 <e7d9d23ecd9172f05b09bb678ff22db8e361c428 || >=9b9960a0ca4773e21c4b153ed355583946346b25 <0380129b1373c437eb35401a174671c8888f4b80 || >=9b9960a0ca4773e21c4b153ed355583946346b25 <c81cef6a805dec266c10fc4f83c93d6fcf1a2b43 || >=9b9960a0ca4773e21c4b153ed355583946346b25 <f9868174af49d207fbaf0c5e055d088a983684af | 3a7fd224df0fbb42167eb1b77be45d72fe0b1098, 29e4478e2ed5a227e8f0c33cacb91bf227cedd47, 65a72b721943618eeb3a41c8b36e915591f3f83f, bee826c00ac900473f91306f1f3e5a5a81fd4a74, e7d9d23ecd9172f05b09bb678ff22db8e361c428, 0380129b1373c437eb35401a174671c8888f4b80, c81cef6a805dec266c10fc4f83c93d6fcf1a2b43, f9868174af49d207fbaf0c5e055d088a983684af |
Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 11, 2026
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix XDR length calculation in nfsd4_ff_encode_layoutget The XDR buffer size calculation in nfsd4_ff_encode_layoutget() has multiple errors that can result in either an out-of-bounds write or leaking uninitialized kernel memory to the client: - fh_len doesn't account for XDR padding on the file handle data - uid and gid lengths use "8 + len" but xdr_encode_opaque() actually writes "4 + xdr_align_size(len)" bytes - ds_len omits the flags and stats_collect_hint fields (8 bytes), while len's header constant overestimates by 8 bytes -- these partially cancel but leave a net mismatch The worst case occurs with short strings (e.g. uid=0, gid=0 with an odd-sized file handle), where the function writes up to 5 bytes past the reserved XDR buffer. Conversely, when string lengths happen to be 4-byte aligned, the reservation is too large and stale buffer content is sent to the client. Fix this by breaking out every encoded field explicitly in the ds_len calculation, using xdr_align_size() for all variable-length opaque fields, and correcting the header constants.
Quoted source text, attributed separately from HOL analysis.