CVE-2026-89656

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-11. A secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

libceph: reject buckets with mismatched CRUSH ids

crush_decode() stores bucket data by array slot, and the mapper later derives the per-bucket workspace index from the decoded bucket id. A malformed map can therefore make one bucket reuse another bucket's workspace by encoding an id different from -1 - slot.

For uniform buckets, the second replica selection expands the source bucket's permutation into that aliased workspace buffer. If the source bucket is larger than the aliased bucket, the write runs past the smaller permutation array and can escape the kvmalloc'd CRUSH workspace. KASAN reports a slab OOB write of 4 bytes in bucket_perm_choose().

Reject buckets whose encoded id does not match their array slot. Valid CRUSH maps already use the canonical negative id corresponding to the bucket slot, so this restores the invariant expected by work->work[-1 - in->id] without changing valid map behavior.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
44
EG Risk 44/100

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 (value × EchelonGraph’s weight)
Severity98% × 45%
The EG Score, 9.8 of 10.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
42nd
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

September 11, 2026

Last Modified

September 14, 2026

Advisory Details (8)

Auto-updated Oct 13, 2026
Patch available.
Web page

libceph: reject buckets with mismatched CRUSH ids - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ee59040d6ed1a5f8d10d27174b8f32c90ca8e89a
Web page

libceph: reject buckets with mismatched CRUSH ids - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/baad5875fdd2f5e248250fc3519bb045d64f1716
Web page

libceph: reject buckets with mismatched CRUSH ids - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/79900d978158b2d80eef952fc41b9e4dc58d7b83
Web page

libceph: reject buckets with mismatched CRUSH ids - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6e5c6ce252b1eccfd41670a5cf95ab44f7ba7022
Web page

libceph: reject buckets with mismatched CRUSH ids - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4aeb93daadf388e72073abc204312dd364eeb30a
Web page

libceph: reject buckets with mismatched CRUSH ids - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3cde4a8302301679937474a5f7a851394cc1bd11
Web page

libceph: reject buckets with mismatched CRUSH ids - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/3516a4131c4e45d62ee4e42e82c36930e8c1fbbd
Web page

libceph: reject buckets with mismatched CRUSH ids - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/00562ccd4e88d092b9b851df50fad20442bfeb24

Vendor Advisories for CVE-2026-89656(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 67× in last 7d / 390× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 409 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 309 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 10:00 UTCEG score recompute
  2. 2026-10-14 10:00 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  4. 2026-10-13 08:10 UTCEG score recompute
  5. 2026-10-13 08:10 UTCVendor advisory
  6. 2026-10-13 08:10 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  8. 2026-10-12 14:48 UTCEG score recompute
  9. 2026-10-12 09:05 UTCEG score recompute
  10. 2026-10-12 09:05 UTCVendor advisory
  11. 2026-10-12 09:05 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-11 21:05 UTCVendor advisory
  13. 2026-10-11 21:05 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  14. 2026-10-11 19:15 UTCEG score recompute
  15. 2026-10-11 16:31 UTCEG score recompute
  16. 2026-10-11 15:25 UTCEG score recompute
  17. 2026-10-11 15:25 UTCVendor advisory
  18. 2026-10-11 15:25 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  19. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  20. 2026-10-11 13:47 UTCEG score recompute
  21. 2026-10-11 11:40 UTCEG score recompute
  22. 2026-10-11 11:40 UTCVendor advisory
  23. 2026-10-11 11:40 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-10-11 06:49 UTCVendor advisory
  25. 2026-10-11 06:49 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
Show 75 more
  1. 2026-10-10 23:49 UTCEG score recompute
  2. 2026-10-10 23:49 UTCVendor advisory
  3. 2026-10-10 23:49 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  5. 2026-10-10 19:43 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-10-10 15:57 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-10-10 11:35 UTCVendor advisory
  8. 2026-10-10 11:35 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-10 07:50 UTCVendor advisory
  10. 2026-10-10 07:49 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-10-10 03:47 UTCVendor advisory
  12. 2026-10-10 03:47 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-10 00:00 UTCVendor advisory
  14. 2026-10-10 00:00 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-10-09 20:16 UTCEG score recompute
  16. 2026-10-09 20:16 UTCVendor advisory
  17. 2026-10-09 20:16 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  19. 2026-10-09 16:31 UTCVendor advisory
  20. 2026-10-09 16:31 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-09 06:43 UTCVendor advisory
  22. 2026-10-09 06:43 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  23. 2026-10-09 02:58 UTCVendor advisory
  24. 2026-10-09 02:58 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-10-08 23:13 UTCEG score recompute
  26. 2026-10-08 23:13 UTCVendor advisory
  27. 2026-10-08 23:13 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  28. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  29. 2026-10-08 10:58 UTCVendor advisory
  30. 2026-10-08 10:57 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  31. 2026-10-08 06:55 UTCVendor advisory
  32. 2026-10-08 06:55 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  33. 2026-10-08 03:11 UTCEG score recompute
  34. 2026-10-08 03:11 UTCVendor advisory
  35. 2026-10-08 03:10 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  36. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  37. 2026-10-07 23:25 UTCVendor advisory
  38. 2026-10-07 23:25 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  39. 2026-10-07 19:40 UTCVendor advisory
  40. 2026-10-07 19:40 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-10-07 13:44 UTCVendor advisory
  42. 2026-10-07 13:44 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  43. 2026-10-07 09:42 UTCVendor advisory
  44. 2026-10-07 09:41 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  45. 2026-10-07 05:54 UTCVendor advisory
  46. 2026-10-07 05:54 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  47. 2026-10-07 02:09 UTCVendor advisory
  48. 2026-10-07 02:09 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  49. 2026-10-06 22:24 UTCVendor advisory
  50. 2026-10-06 22:24 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  51. 2026-10-06 18:39 UTCEG score recompute
  52. 2026-10-06 18:39 UTCVendor advisory
  53. 2026-10-06 18:39 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  54. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  55. 2026-10-06 14:54 UTCVendor advisory
  56. 2026-10-06 14:54 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  57. 2026-10-06 11:07 UTCVendor advisory
  58. 2026-10-06 11:07 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  59. 2026-10-06 07:23 UTCVendor advisory
  60. 2026-10-06 07:23 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-10-06 03:38 UTCVendor advisory
  62. 2026-10-06 03:38 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  63. 2026-10-05 23:53 UTCVendor advisory
  64. 2026-10-05 23:53 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-10-05 20:08 UTCEG score recompute
  66. 2026-10-05 20:08 UTCVendor advisory
  67. 2026-10-05 20:08 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  68. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  69. 2026-10-05 16:22 UTCVendor advisory
  70. 2026-10-05 16:22 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  71. 2026-10-05 11:46 UTCVendor advisory
  72. 2026-10-05 11:46 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  73. 2026-10-05 08:01 UTCVendor advisory
  74. 2026-10-05 08:01 UTCGHSA enrichmentGHSA-qwcm-8gh9-xc6h · GitHub severity CRITICAL · GitHub CVSS 9.8
  75. 2026-10-05 04:16 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-89656?
CVE-2026-89656 is a critical-severity vulnerability; its CVE record was published on September 11, 2026. In the Linux kernel, the following vulnerability has been resolved: libceph: reject buckets with mismatched CRUSH ids crush_decode() stores bucket data by array slot, and the mapper later derives the per-bucket workspace index from the decoded bucket id. A malformed map can therefore make one…
When was the CVE record for CVE-2026-89656 published?
The CVE record for CVE-2026-89656 was published on September 11, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 14, 2026; the record at its source may have been updated since.
Is CVE-2026-89656 actively exploited?
CVE-2026-89656 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (42nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-89656?
CVE-2026-89656 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-89656?
A fix for CVE-2026-89656 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-89656 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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