CVE-2026-93813

HIGHPre-NVD 7.87.8—
EchelonGraph scoreHIGH confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-24. 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 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:

btrfs: tree-checker: validate INODE_REF's namelen

[BUG] A crafted btrfs image can trigger the following crash:

BUG: unable to handle page fault for address: ffffd1dc42884000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page CPU: 9 UID: 0 PID: 1034 Comm: poc Not tainted 7.1.0-rc4-custom+ #383 PREEMPT(full) 46af0a92938a63be7132e0dfd71e62327c51d5c2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:memcpy+0xc/0x10 Call Trace: read_extent_buffer+0xe4/0x100 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f] btrfs_get_name+0x15e/0x1e0 [btrfs 3cf0785dd58fec8c5ff84633b772f17ce1f92a8f] reconnect_path+0x165/0x390 exportfs_decode_fh_raw+0x337/0x400 ? drop_caches_sysctl_handler+0xb0/0xb0 ---[ end trace 0000000000000000 ]--- RIP: 0010:memcpy+0xc/0x10 Kernel panic - not syncing: Fatal exception

[CAUSE] TThe crafted image has the following corrupted INODE_REF item:

item 9 key (258 INODE_REF 257) itemoff 11544 itemsize 4106 index 2 namelen 4096 name: d\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000

The itemsize matches the namelen, but the namelen is 4096, way larger than normal name length limit (BTRFS_NAME_LEN, 255).

Meanwhile the memory of the @name is only 255 byte sized, this will cause out-of-boundary access, and cause the above crash.

[FIX] Add extra namelen verification for INODE_REF, just like what we have done in ROOT_REF checks.

Now the crafted image can be rejected gracefully:

BTRFS critical (device dm-2): corrupt leaf: root=5 block=30572544 slot=14 ino=259, invalid inode ref name length, has 4096 expect [1, 255] BTRFS error (device dm-2): read time tree block corruption detected on logical 30572544 mirror 2

[ Rebase, add a Link: tag, add an simple cause analyze ]

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
2nd
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 24, 2026

Last Modified

October 3, 2026

Advisory Details (3)

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

btrfs: tree-checker: validate INODE_REF's namelen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/eeddee090b834a7d4b6a8214d2e3739e64c7a338
generic

btrfs: tree-checker: validate INODE_REF's namelen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8f75c19892263bc0555fba922aefe103e841e86d
generic

btrfs: tree-checker: validate INODE_REF's namelen - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3dc22abc21f5892406c09202fa2627196cc96967

Vendor Advisories for CVE-2026-93813(2)

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

Affected Packages

(4 across 3 ecosystems)
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (360 versions)
  • every version on: no fix on record
—
linux-6.126.12.100-1~deb12u1, 6.12.101-1~deb12u1, 6.12.107-1~deb12u1
  • every version up to 6.12.111-1~deb12u1: fixed in 6.12.111-1~deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 6.12.96-1 (35 versions)
  • every version up to 6.12.111-1: fixed in 6.12.111-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (179 versions)
  • every version up to 7.2.6-1: fixed in 7.2.6-1
—

Data Freshness Timeline

(refreshed 40× in last 7d / 60× 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 02:30 UTCEG score recompute
  2. 2026-10-05 02:30 UTCVendor advisory
  3. 2026-10-05 02:30 UTCGHSA enrichment
  4. 2026-10-04 23:23 UTCEPSS rescore
  5. 2026-10-04 13:31 UTCVendor advisory
  6. 2026-10-04 13:31 UTCGHSA enrichment
  7. 2026-10-04 00:31 UTCEG score recompute
  8. 2026-10-04 00:31 UTCVendor advisory
  9. 2026-10-04 00:31 UTCGHSA enrichment
  10. 2026-10-03 14:26 UTCEPSS rescore
  11. 2026-10-03 11:32 UTCVendor advisory
  12. 2026-10-03 11:32 UTCGHSA enrichment
  13. 2026-10-03 06:09 UTCEG score recompute
  14. 2026-10-03 06:09 UTCVendor advisory
  15. 2026-10-03 06:09 UTCGHSA enrichment
  16. 2026-10-02 17:09 UTCVendor advisory
  17. 2026-10-02 17:09 UTCGHSA enrichment
  18. 2026-10-02 04:10 UTCEG score recompute
  19. 2026-10-02 04:10 UTCVendor advisory
  20. 2026-10-02 04:10 UTCGHSA enrichment
  21. 2026-10-01 19:51 UTCEPSS rescore
  22. 2026-10-01 15:04 UTCVendor advisory
  23. 2026-10-01 15:04 UTCGHSA enrichment
  24. 2026-10-01 02:05 UTCEG score recompute
  25. 2026-10-01 02:05 UTCVendor advisory
Show 35 more
  1. 2026-10-01 02:05 UTCGHSA enrichment
  2. 2026-09-30 15:04 UTCEPSS rescore
  3. 2026-09-30 13:04 UTCVendor advisory
  4. 2026-09-30 13:04 UTCGHSA enrichment
  5. 2026-09-29 23:55 UTCEG score recompute
  6. 2026-09-29 23:55 UTCVendor advisory
  7. 2026-09-29 23:55 UTCGHSA enrichment
  8. 2026-09-29 08:22 UTCEG score recompute
  9. 2026-09-29 08:22 UTCVendor advisory
  10. 2026-09-29 08:22 UTCGHSA enrichment
  11. 2026-09-28 19:23 UTCEG score recompute
  12. 2026-09-28 19:23 UTCVendor advisory
  13. 2026-09-28 19:22 UTCGHSA enrichment
  14. 2026-09-28 13:52 UTCEPSS rescore
  15. 2026-09-28 13:52 UTCEPSS rescore
  16. 2026-09-28 06:20 UTCGHSA enrichment
  17. 2026-09-27 17:21 UTCEG score recompute
  18. 2026-09-27 17:21 UTCGHSA enrichment
  19. 2026-09-27 13:49 UTCEPSS rescore
  20. 2026-09-27 04:22 UTCEG score recompute
  21. 2026-09-27 04:22 UTCGHSA enrichment
  22. 2026-09-26 15:59 UTCEPSS rescore
  23. 2026-09-26 15:22 UTCGHSA enrichment
  24. 2026-09-26 02:23 UTCEG score recompute
  25. 2026-09-26 02:23 UTCGHSA enrichment
  26. 2026-09-25 13:23 UTCEG score recompute
  27. 2026-09-25 13:22 UTCGHSA enrichment
  28. 2026-09-25 12:56 UTCEG score recompute
  29. 2026-09-25 12:56 UTCGHSA enrichment
  30. 2026-09-25 05:17 UTCEG score recompute▲ 7.80
  31. 2026-09-25 05:17 UTCGHSA enrichment
  32. 2026-09-25 05:16 UTCMITRE cvelistV5CVSS v3 → 7.8 · severity → HIGH
  33. 2026-09-24 17:33 UTCNVD update
  34. 2026-09-24 16:30 UTCEG score recompute
  35. 2026-09-24 16:26 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-93813?
CVE-2026-93813 is a high vulnerability published on September 24, 2026. In the Linux kernel, the following vulnerability has been resolved: btrfs: tree-checker: validate INODE_REF's namelen [BUG] A crafted btrfs image can trigger the following crash: BUG: unable to handle page fault for address: ffffd1dc42884000 #PF: supervisor write access in kernel mode #PF:…
When was CVE-2026-93813 disclosed?
CVE-2026-93813 was first published on September 24, 2026, with the most recent update on October 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-93813 actively exploited?
CVE-2026-93813 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (2nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-93813?
CVE-2026-93813 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-2026-93813?
No fix for CVE-2026-93813 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-2026-93813 are linked in the Vendor Advisories panel on this page.

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