Answer in brief
CVE-2026-52906 records a High severity (CVSS 7.7) vulnerability in 9p: fix access mode flags being ORed instead of replaced. The current sources do not mark it as known exploited. The current feed maps 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 7.7. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=1f3e4142c0eb178089ea0cbc97506a061470ad27 <b8f037e87a083291190204b959cda417aaf01058 || >=1f3e4142c0eb178089ea0cbc97506a061470ad27 <da2346a48a5a1fed86c3fe3d73c0b60e7b3027c9 | b8f037e87a083291190204b959cda417aaf01058, da2346a48a5a1fed86c3fe3d73c0b60e7b3027c9 |
| Linux/Linuxgeneric | 6.19 | Not reported |
Published upstream
Jun 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 7, 2026
In the Linux kernel, the following vulnerability has been resolved: 9p: fix access mode flags being ORed instead of replaced Since commit 1f3e4142c0eb ("9p: convert to the new mount API"), v9fs_apply_options() applies parsed mount flags with |= onto flags already set by v9fs_session_init(). For 9P2000.L, session_init sets V9FS_ACCESS_CLIENT as the default, so when the user mounts with "access=user", both bits end up set. Access mode checks compare against exact values, so having both bits set matches neither mode. This causes v9fs_fid_lookup() to fall through to the default switch case, using INVALID_UID (nobody/65534) instead of current_fsuid() for all fid lookups. Root is then unable to chown or perform other privileged operations. Fix by clearing the access mask before applying the user's choice.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-52906 records a High severity (CVSS 7.7) vulnerability in 9p: fix access mode flags being ORed instead of replaced. The current sources do not mark it as known exploited. The current feed maps 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 7.7. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=1f3e4142c0eb178089ea0cbc97506a061470ad27 <b8f037e87a083291190204b959cda417aaf01058 || >=1f3e4142c0eb178089ea0cbc97506a061470ad27 <da2346a48a5a1fed86c3fe3d73c0b60e7b3027c9 | b8f037e87a083291190204b959cda417aaf01058, da2346a48a5a1fed86c3fe3d73c0b60e7b3027c9 |
| Linux/Linuxgeneric | 6.19 | Not reported |
Published upstream
Jun 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 7, 2026
In the Linux kernel, the following vulnerability has been resolved: 9p: fix access mode flags being ORed instead of replaced Since commit 1f3e4142c0eb ("9p: convert to the new mount API"), v9fs_apply_options() applies parsed mount flags with |= onto flags already set by v9fs_session_init(). For 9P2000.L, session_init sets V9FS_ACCESS_CLIENT as the default, so when the user mounts with "access=user", both bits end up set. Access mode checks compare against exact values, so having both bits set matches neither mode. This causes v9fs_fid_lookup() to fall through to the default switch case, using INVALID_UID (nobody/65534) instead of current_fsuid() for all fid lookups. Root is then unable to chown or perform other privileged operations. Fix by clearing the access mask before applying the user's choice.
Quoted source text, attributed separately from HOL analysis.