Answer in brief
CVE-2026-89713 records a Critical severity (CVSS 9.1) vulnerability in NFSD: check truncate permission under inode lock. 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 9.1. 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 | >=783112f7401ff449d979530209b3f6c2594fdb4e <3afa17d93ba8c925f49370c816c6dae5112d8c24 || >=783112f7401ff449d979530209b3f6c2594fdb4e <d8352da196349182e1afd5a93308256cddc0a97d || >=783112f7401ff449d979530209b3f6c2594fdb4e <44086254479035de42ca3d286ecf25521d4e6325 || >=783112f7401ff449d979530209b3f6c2594fdb4e <b778e0e0a16759f22a70579c3cf8d254a40d4a7f || 604a3c407026d6162d15300478e63f901e435efc || cc4d5dc73841b98d33cdfb9822d70b0aac4beca5 || 3ee4f442e5b37a537297b812557b1163f96b5399 || a3c6cbc4eac4473ed5461d5faae2794d3e5c0e44 || 982898d7f97a35447403c3fcecc0d96c646ce101 || >=3.2.89 <3.3 || >=3.16.44 <3.17 || >=4.4.53 <4.5 || >=4.9.14 <4.10 || >=4.10.2 <4.11 | 3afa17d93ba8c925f49370c816c6dae5112d8c24, d8352da196349182e1afd5a93308256cddc0a97d, 44086254479035de42ca3d286ecf25521d4e6325, b778e0e0a16759f22a70579c3cf8d254a40d4a7f, 3.3, 3.17, 4.5, 4.10, 4.11 |
| Linux/Linuxgeneric | 4.11 | Not reported |
| Linux/Linuxgeneric | >=783112f7401ff449d979530209b3f6c2594fdb4e <52d0c5bdfe232c9974d4b11f97078b9c7814f05d || >=783112f7401ff449d979530209b3f6c2594fdb4e <3afa17d93ba8c925f49370c816c6dae5112d8c24 || >=783112f7401ff449d979530209b3f6c2594fdb4e <d8352da196349182e1afd5a93308256cddc0a97d || >=783112f7401ff449d979530209b3f6c2594fdb4e <44086254479035de42ca3d286ecf25521d4e6325 || >=783112f7401ff449d979530209b3f6c2594fdb4e <b778e0e0a16759f22a70579c3cf8d254a40d4a7f || 604a3c407026d6162d15300478e63f901e435efc || cc4d5dc73841b98d33cdfb9822d70b0aac4beca5 || 3ee4f442e5b37a537297b812557b1163f96b5399 || a3c6cbc4eac4473ed5461d5faae2794d3e5c0e44 || 982898d7f97a35447403c3fcecc0d96c646ce101 || >=3.2.89 <3.3 || >=3.16.44 <3.17 || >=4.4.53 <4.5 || >=4.9.14 <4.10 || >=4.10.2 <4.11 | 52d0c5bdfe232c9974d4b11f97078b9c7814f05d, 3afa17d93ba8c925f49370c816c6dae5112d8c24, d8352da196349182e1afd5a93308256cddc0a97d, 44086254479035de42ca3d286ecf25521d4e6325, b778e0e0a16759f22a70579c3cf8d254a40d4a7f, 3.3, 3.17, 4.5, 4.10, 4.11 |
Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 21, 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: check truncate permission under inode lock nfsd_setattr() checks whether a size update needs NFSD_MAY_TRUNC before it takes inode_lock(). The comparison uses the file size sampled by that unlocked read, but the actual ATTR_SIZE update is applied later under inode_lock() by notify_change(). This leaves a TOCTOU window for append-only files. If a client sends a SETATTR that does not shrink the file at the time of the unlocked sample, a concurrent append can extend the file before nfsd_setattr() takes inode_lock(). notify_change() then applies a real truncation without the NFSD_MAY_TRUNC check that rejects IS_APPEND(inode). The VFS truncate syscall paths perform their own append-only checks before calling notify_change(), so NFSD must make this decision against the locked size it is about to change. Split the write-count acquisition from the truncation permission check. Keep get_write_access() before the locked setattr work, then recheck whether the requested size is below i_size_read(inode) after inode_lock() has been acquired and before notify_change(ATTR_SIZE). This also avoids the plain unlocked inode->i_size load.
Quoted source text, attributed separately from HOL analysis.