CVE-2026-97971

HIGHPre-NVD 7.87.8—
EchelonGraph scoreHIGH confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-25. A secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
7.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 7.8Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

In the Linux kernel, the following vulnerability has been resolved:

nstree: check listing permission before taking a namespace reference

legitimize_ns() takes a reference on the candidate namespace before may_list_ns() has decided whether the caller may see it. The __free(ns_put) cleanup on the denied path can drop the last reference to a mount namespace while we still hold the rcu read lock, and put_mnt_ns() may sleep there. This is the same problem commit 2ec2aff3c8e2 ("ns: make sure reference are dropped outside of rcu lock") fixed for the put_user() path. Neither ns_requested() nor may_list_ns() needs a reference, both only look at the namespace type and at the caller's own namespaces, so do the checks first and take the reference last.

Splat:

Voluntary context switch within RCU read-side critical section! WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0x238/0x2a0, CPU#5: a/3442 CPU: 5 UID: 1000 PID: 3442 Comm: a Not tainted 7.0.0-30-generic #30-Ubuntu PREEMPT(lazy) RIP: 0010:rcu_note_context_switch+0x238/0x2a0 Call Trace: __schedule+0xcf/0x650 schedule+0x27/0x90 schedule_preempt_disabled+0x15/0x30 __mutex_lock.constprop.0+0x550/0xaf0 __mutex_lock_slowpath+0x13/0x20 mutex_lock+0x3b/0x50 exp_funnel_lock+0xb2/0x260 synchronize_rcu_expedited+0xe7/0x220 namespace_unlock+0x26a/0x320 put_mnt_ns+0xd3/0x120 mntns_put+0xe/0x20 do_listns+0x13e/0x560 __do_sys_listns+0x126/0x2d0 __x64_sys_listns+0x20/0x30 x64_sys_call+0x2366/0x2390 do_syscall_64+0x105/0x5a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e

CVSS v3
7.8
EG Score
7.8HIGHhigh confidence
EG Risk
40
EG Risk 40/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.1%
EPSS %ILE
1st
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 25, 2026

Last Modified

September 25, 2026

Advisory Details (2)

Auto-updated Sep 25, 2026
No patch confirmed yet.
generic

nstree: check listing permission before taking a namespace reference - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/56ea4e86832d8abe8930394473566c194d189f85
generic

nstree: check listing permission before taking a namespace reference - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9e673bf5d88aa898e52cef5c87058c3fa845bc71

Vendor Advisories for CVE-2026-97971(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (179 versions)
  • every version up to 7.2.7-1: fixed in 7.2.7-1
—

Data Freshness Timeline

(refreshed 29× in last 7d / 47× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-05 04:03 UTCEG score recompute
  2. 2026-10-05 04:03 UTCGHSA enrichment
  3. 2026-10-04 23:23 UTCEPSS rescore
  4. 2026-10-04 16:44 UTCGHSA enrichment
  5. 2026-10-04 05:27 UTCGHSA enrichment
  6. 2026-10-03 18:09 UTCEG score recompute
  7. 2026-10-03 18:09 UTCGHSA enrichment
  8. 2026-10-03 14:26 UTCEPSS rescore
  9. 2026-10-03 06:50 UTCGHSA enrichment
  10. 2026-10-02 19:33 UTCEG score recompute
  11. 2026-10-02 19:33 UTCGHSA enrichment
  12. 2026-10-02 17:57 UTCEPSS rescore
  13. 2026-10-02 08:16 UTCGHSA enrichment
  14. 2026-10-01 20:59 UTCEG score recompute
  15. 2026-10-01 20:59 UTCGHSA enrichment
  16. 2026-10-01 19:51 UTCEPSS rescore
  17. 2026-10-01 09:42 UTCGHSA enrichment
  18. 2026-09-30 22:25 UTCEG score recompute
  19. 2026-09-30 22:25 UTCGHSA enrichment
  20. 2026-09-30 15:04 UTCEPSS rescore
  21. 2026-09-30 11:08 UTCGHSA enrichment
  22. 2026-09-29 23:50 UTCEG score recompute
  23. 2026-09-29 23:50 UTCGHSA enrichment
  24. 2026-09-29 09:48 UTCGHSA enrichment
  25. 2026-09-28 22:31 UTCEG score recompute
Show 22 more
  1. 2026-09-28 22:31 UTCGHSA enrichment
  2. 2026-09-28 13:52 UTCEPSS rescore
  3. 2026-09-28 13:52 UTCEPSS rescore
  4. 2026-09-28 11:14 UTCGHSA enrichment
  5. 2026-09-27 23:57 UTCEG score recompute
  6. 2026-09-27 23:57 UTCGHSA enrichment
  7. 2026-09-27 13:49 UTCEPSS rescore
  8. 2026-09-27 12:39 UTCGHSA enrichment
  9. 2026-09-27 01:21 UTCEG score recompute
  10. 2026-09-27 01:21 UTCGHSA enrichment
  11. 2026-09-26 15:59 UTCEPSS rescore
  12. 2026-09-26 14:02 UTCGHSA enrichment
  13. 2026-09-26 02:44 UTCEG score recompute
  14. 2026-09-26 02:44 UTCGHSA enrichment
  15. 2026-09-25 15:24 UTCEG score recompute
  16. 2026-09-25 15:24 UTCGHSA enrichment
  17. 2026-09-25 14:52 UTCEG score recompute▲ 7.80
  18. 2026-09-25 14:52 UTCGHSA enrichment
  19. 2026-09-25 14:49 UTCMITRE cvelistV5CVSS v3 → 7.8 · severity → HIGH
  20. 2026-09-25 11:30 UTCNVD update
  21. 2026-09-25 10:32 UTCEG score recompute
  22. 2026-09-25 10:27 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-97971?
CVE-2026-97971 is a high vulnerability published on September 25, 2026. In the Linux kernel, the following vulnerability has been resolved: nstree: check listing permission before taking a namespace reference legitimize_ns() takes a reference on the candidate namespace before maylistns() has decided whether the caller may see it. The free(ns_put) cleanup on the denied…
When was CVE-2026-97971 disclosed?
CVE-2026-97971 was first published on September 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-97971 actively exploited?
CVE-2026-97971 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-97971?
CVE-2026-97971 has a CVSS base score of 7.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-97971?
No fix for CVE-2026-97971 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-97971 are linked in the Vendor Advisories panel on this page.

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