CVE-2026-89536

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 — 3 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: 0.6%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

SUNRPC: wait for in-flight client TLS handshake callback

xs_tls_handshake_sync() gives xs_tls_handshake_done() a reference to the lower transport before submitting the handshake request. On timeout or signal, the synchronous waiter drops that reference after calling tls_handshake_cancel().

handshake_req_cancel() returns false when handshake_complete() has already marked the request complete. In that case the completion callback can still be running, so dropping the callback-owned reference in the waiter can free the lower transport before xs_tls_handshake_done() stores xprt_err or drops its own reference.

If cancellation loses to completion, wait until xs_tls_handshake_done() signals handshake_done and let the callback release its reference. This mirrors the server-side handshake lifetime handling and keeps the timeout or signal return value unchanged.

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.
Exploitation0.6% × 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
0.6%
EPSS %ILE
49th
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 (5)

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

SUNRPC: wait for in-flight client TLS handshake callback - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/fb43997407bc17ee39bac81ab708101312e255f5
Web page

SUNRPC: wait for in-flight client TLS handshake callback - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a89dd597458848b463d284b15e42a8078beeb046
Web page

SUNRPC: wait for in-flight client TLS handshake callback - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7fbb6d2ab0391eb8d1f1a68e6bc263ef02cea61b
Web page

SUNRPC: wait for in-flight client TLS handshake callback - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1de391e8b94e31b45c19c16dbf315e294810c7de
Web page

SUNRPC: wait for in-flight client TLS handshake callback - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/15431820f448e09f8029b670d5c82aa5917d4625

Vendor Advisories for CVE-2026-89536(1)

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

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
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 42× in last 7d / 223× 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 242 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 142 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  2. 2026-10-13 11:03 UTCEG score recompute
  3. 2026-10-13 11:03 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  5. 2026-10-12 14:48 UTCEG score recompute
  6. 2026-10-12 09:07 UTCEG score recompute
  7. 2026-10-12 09:06 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  8. 2026-10-11 21:10 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-11 19:15 UTCEG score recompute
  10. 2026-10-11 16:32 UTCEG score recompute
  11. 2026-10-11 15:30 UTCEG score recompute
  12. 2026-10-11 15:30 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  14. 2026-10-11 13:47 UTCEG score recompute
  15. 2026-10-11 11:41 UTCEG score recompute
  16. 2026-10-11 11:40 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-11 06:52 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-10 23:08 UTCEG score recompute
  19. 2026-10-10 23:08 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  21. 2026-10-10 18:31 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-10-10 14:36 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  23. 2026-10-10 10:46 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-10-10 06:44 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-10-10 02:54 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
Show 75 more
  1. 2026-10-09 23:04 UTCEG score recompute
  2. 2026-10-09 23:04 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  4. 2026-10-09 19:16 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-10-09 06:58 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-10-09 03:09 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-10-08 23:20 UTCEG score recompute
  8. 2026-10-08 23:20 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  10. 2026-10-08 10:58 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  11. 2026-10-08 07:09 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-08 03:20 UTCEG score recompute
  13. 2026-10-08 03:20 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  15. 2026-10-07 23:32 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  16. 2026-10-07 19:44 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-07 11:48 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-07 07:46 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  19. 2026-10-07 03:57 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-10-07 00:09 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-06 20:19 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-10-06 16:23 UTCEG score recompute
  23. 2026-10-06 16:23 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  25. 2026-10-06 12:32 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  26. 2026-10-06 08:43 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  27. 2026-10-06 04:39 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  28. 2026-10-06 00:48 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  29. 2026-10-05 20:59 UTCEG score recompute
  30. 2026-10-05 20:59 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  31. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  32. 2026-10-05 17:11 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  33. 2026-10-05 13:22 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  34. 2026-10-05 09:16 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  35. 2026-10-05 05:28 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  36. 2026-10-05 01:39 UTCEG score recompute
  37. 2026-10-05 01:39 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  38. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  39. 2026-10-04 21:51 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  40. 2026-10-04 18:02 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-10-04 13:56 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  42. 2026-10-04 10:08 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  43. 2026-10-04 06:20 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  44. 2026-10-04 02:32 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  45. 2026-10-03 22:43 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  46. 2026-10-03 18:55 UTCEG score recompute
  47. 2026-10-03 18:54 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  48. 2026-10-03 14:07 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  49. 2026-10-03 10:13 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  50. 2026-10-03 04:37 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  51. 2026-10-03 00:48 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  52. 2026-10-02 20:59 UTCEG score recompute
  53. 2026-10-02 20:59 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  54. 2026-10-02 17:11 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  55. 2026-10-02 13:22 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  56. 2026-10-02 09:34 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  57. 2026-10-02 05:46 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  58. 2026-10-02 01:09 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  59. 2026-10-01 21:00 UTCEG score recompute
  60. 2026-10-01 21:00 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  62. 2026-10-01 17:11 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  63. 2026-10-01 12:37 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  64. 2026-10-01 08:49 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-10-01 05:01 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  66. 2026-10-01 01:08 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  67. 2026-09-30 21:20 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  68. 2026-09-30 17:32 UTCEG score recompute
  69. 2026-09-30 17:32 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  70. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  71. 2026-09-30 13:41 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-09-30 09:35 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  73. 2026-09-30 05:39 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  74. 2026-09-30 01:44 UTCGHSA enrichmentGHSA-fhrg-h295-8p3m · GitHub severity CRITICAL · GitHub CVSS 9.8
  75. 2026-09-29 16:02 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-89536?
CVE-2026-89536 is a critical-severity vulnerability; its CVE record was published on September 11, 2026. In the Linux kernel, the following vulnerability has been resolved: SUNRPC: wait for in-flight client TLS handshake callback xstlshandshakesync() gives xstlshandshakedone() a reference to the lower transport before submitting the handshake request. On timeout or signal, the synchronous waiter drops…
When was the CVE record for CVE-2026-89536 published?
The CVE record for CVE-2026-89536 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-2026-89536 actively exploited?
CVE-2026-89536 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (49th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-89536?
CVE-2026-89536 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-2026-89536?
A fix for CVE-2026-89536 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-89536 are linked in the Vendor Advisories panel on this page.

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