CVE-2026-63802

HIGHPre-NVD 7.87.8—
EchelonGraph scoreHIGH confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-19. a secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 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:

blk-cgroup: fix UAF in __blkcg_rstat_flush()

When multiple blkgs in the same blkcg are released concurrently, a use-after-free can occur. The race happens when one blkg's __blkcg_rstat_flush() removes another blkg's iostat entries via llist_del_all(). The second blkg sees an empty list and proceeds to free itself while the first is still iterating over its entries.

Move the flush from __blkg_release() (RCU callback) to blkg_release() (before call_rcu). This ensures the RCU grace period waits for any concurrent flush's rcu_read_lock() section to complete before freeing.

CVSS v3
7.8
EG Score
7.8(high)
EG Risk
40(Track)
EG Risk 40/100SSVC: Track

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%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
3%
KEV
Not listed

Published

July 19, 2026

Last Modified

July 20, 2026

Advisory Details (5)

Auto-updated Jul 21, 2026
No patch confirmed yet.
generic

blk-cgroup: fix UAF in __blkcg_rstat_flush() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/bbebd9425cad3573d1527441753899b926525a0f
generic

blk-cgroup: fix UAF in __blkcg_rstat_flush() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/afebe44facc48a61761e885bbb7f0380d4a603ec
generic

blk-cgroup: fix UAF in __blkcg_rstat_flush() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/96e545410c4f74c89d496c1d5d9ef8d08f14368b
generic

blk-cgroup: fix UAF in __blkcg_rstat_flush() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c6
generic

blk-cgroup: fix UAF in __blkcg_rstat_flush() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0ab5ee5a1badb58cbb2242617cb01a4972b1f2a2

Vendor Advisories for CVE-2026-63802(2)

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 21× in last 7d / 24× 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. 2026-07-26 23:15 UTCEG score recompute
  2. 2026-07-26 23:15 UTCGHSA enrichment
  3. 2026-07-26 14:54 UTCEPSS rescore
  4. 2026-07-26 14:54 UTCEPSS rescore
  5. 2026-07-26 11:10 UTCEG score recompute
  6. 2026-07-26 11:10 UTCGHSA enrichment
  7. 2026-07-24 14:18 UTCEPSS rescore
  8. 2026-07-24 14:18 UTCEPSS rescore
  9. 2026-07-23 14:18 UTCEPSS rescore
  10. 2026-07-23 14:18 UTCEPSS rescore
  11. 2026-07-23 03:22 UTCEG score recompute
  12. 2026-07-22 14:08 UTCEPSS rescore
  13. 2026-07-22 14:08 UTCEPSS rescore
  14. 2026-07-21 15:25 UTCEPSS rescore
  15. 2026-07-21 15:25 UTCEPSS rescore
  16. 2026-07-20 17:46 UTCEG score recompute
  17. 2026-07-20 17:46 UTCGHSA enrichment
  18. 2026-07-20 17:08 UTCEPSS rescore
  19. 2026-07-20 14:45 UTCEG score recompute▲ 7.80
  20. 2026-07-20 14:45 UTCGHSA enrichment
  21. 2026-07-20 14:32 UTCMITRE cvelistV5CVSS v3 → 7.8 · severity → HIGH
  22. 2026-07-19 12:26 UTCNVD update
  23. 2026-07-19 12:14 UTCEG score recompute
  24. 2026-07-19 12:10 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-63802?
CVE-2026-63802 is a high vulnerability published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix UAF in blkcgrstatflush() When multiple blkgs in the same blkcg are released concurrently, a use-after-free can occur. The race happens when one blkg's blkcgrstatflush() removes another blkg's iostat entries via…
When was CVE-2026-63802 disclosed?
CVE-2026-63802 was first published in the National Vulnerability Database on July 19, 2026, with the most recent update on July 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63802 actively exploited?
CVE-2026-63802 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 97.4% of all scored CVEs.
What is the CVSS score of CVE-2026-63802?
CVE-2026-63802 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-63802?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63802, 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.

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