CVE-2026-99131

LOWCVSS 8.2 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

In the Linux kernel, the following vulnerability has been resolved: xfs: fix capability check in xfs An user reported a bug where he managed to evade group's quota by changing a file's gid to a different group id the same user belonged to, even though quotas were enforced on both gids and the file's size was big enough to exceed the quota's hardlimit. Commit eba0549bc7d1 replaced a capable() call by a has_capability_noaudit() to prevent unnecessary selinux audit messages. Turns out that both calls have slightly different semantics even though their documentation seems similar. Where in a nutshell: capable() - Tests the task's effective credentials has_ns_capability_noaudit() - Tests the task's real credentials This most of the time has no practical difference but in some cases like changing attrs (specifically group id in this case) through a NFS client this will allow the quota code to use XFS_QMOPT_FORCE_RES, effectively bypassing quota accounting checks. Using instead ns_capable_noaudit() should fix this issue and prevent selinux audit messages. This also fix the remaining calls to has_capability_noaudit()

0.0/ 10 priority

Sources & remediation

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

STABLE

Threat summary

  • 2 mentions across 2 observed days
  • Momentum state: stable

What's happening

  • Peaked 1d ago at 1 mentions (2026-10-31); latest day: 1
  • 2 total mentions across 2 days

Deep dive

Activity timeline2 mentions / 2d
00111Mentions · 2026-10-31: 1Mentions · 2026-11-01: 110-3111-01
Referenced assets2 URLs
Full discourse2 posts
  • cve.now@cvedotnow

    🔴 Linux kernel: quota enforcement bypass in XFS (CVE-2026-99131) A user can change a file's group ID to evade group quota limits and exceed the quota's hard limit. Disclosed Oct 28 Patch → 6.1.191, 6.6.161 and more https://cve.now/CVE-2026-99131?utm_source=x&utm_medium=social&utm_campaign=cvedotnow&utm_content=critical

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  • m.shiono@shioccii

    ほか CVE-2026-99131(XFS クォータ回避, 8.2)も対象。 スコアはNVD未分析(https://kernel.org CNA値)です。ディストリ各社のアドバイザリで修正版カーネルを確認してください。 #CVE #脆弱性

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