CVE-2026-53271

NONEPre-NVD 0.0
0.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No confirmed exploitation signals yet
CISA-KEV: Not listedEPSS: 0%CVSS: —Exploit: NoneExposed: 0

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

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

ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers

smb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn into a local with neither READ_ONCE() nor a NULL check. Both run from oplock_break() after opinfo_get_list() has dropped ci->m_lock, so a concurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL under ci->m_lock within that window. ksmbd_conn_r_count_inc(conn) then writes through NULL at offset 0xc4 -- a remotely triggerable oops.

Guard both reads the way compare_guid_key() already does: read opinfo->conn with READ_ONCE() and return early if it is NULL, before allocating the work struct so nothing leaks. A NULL conn means the client is gone and the break is moot, so return 0; oplock_break() treats that as success and runs the normal teardown.

CVSS v3
—
EG Score
0.0(none)
EPSS
5.9%
KEV
Not listed

Published

June 25, 2026

Last Modified

June 30, 2026

References (5)

Vendor Advisories for CVE-2026-53271(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 22× 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. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 15:33 UTCGHSA enrichment
  4. 2026-07-05 02:31 UTCEPSS rescore
  5. 2026-07-05 02:30 UTCEPSS rescore
  6. 2026-07-04 06:31 UTCEPSS rescore
  7. 2026-07-04 06:31 UTCEPSS rescore
  8. 2026-07-03 20:11 UTCGHSA enrichment
  9. 2026-07-01 15:07 UTCEPSS rescore
  10. 2026-07-01 00:48 UTCGHSA enrichment
  11. 2026-06-30 23:22 UTCEPSS rescore
  12. 2026-06-29 14:06 UTCEPSS rescore
  13. 2026-06-29 14:06 UTCEPSS rescore
  14. 2026-06-28 14:07 UTCEPSS rescore
  15. 2026-06-28 05:25 UTCEG score recompute
  16. 2026-06-28 05:25 UTCGHSA enrichment
  17. 2026-06-28 04:56 UTCEPSS rescore
  18. 2026-06-28 04:56 UTCEPSS rescore
  19. 2026-06-27 03:08 UTCEPSS rescore
  20. 2026-06-25 13:49 UTCEPSS rescore
  21. 2026-06-25 10:03 UTCEG score recompute
  22. 2026-06-25 10:03 UTCGHSA enrichment

Frequently asked(4)

What is CVE-2026-53271?
CVE-2026-53271 is a none vulnerability published on June 25, 2026. In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers smb2oplockbreaknoti() and smb2leasebreaknoti() read opinfo->conn into a local with neither READ_ONCE() nor a NULL check. Both run from oplockbreak() after…
When was CVE-2026-53271 disclosed?
CVE-2026-53271 was first published in the National Vulnerability Database on June 25, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53271 actively exploited?
CVE-2026-53271 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 5.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
How do I remediate CVE-2026-53271?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53271, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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