CVE-2026-98171

HIGHPre-NVD 8.88.8
EchelonGraph scoreHIGH confidence

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

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-10-06. A secondary CVSS source baseline 8.8; 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
8.8EG
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: 8.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs

Fix several related bounds checking and pointer lifecycle issues in receive_encrypted_standard()'s handling of compound encrypted frames:

  • Clear next_buffer after assigning it to server->bigbuf. A stale
next_buffer pointer can lead to a use-after-free on subsequent error paths.
  • Update pdu_length to the decrypted plaintext size (buf_size). Using
the pre-decryption length allows NextCommand to point into stale ciphertext residue.
  • Reject next_cmd values smaller than MID_HEADER_SIZE(server).
  • Fix an integer overflow in the upper bound check by verifying
pdu_length - next_cmd < MID_HEADER_SIZE(server), ensuring the trailing slice is large enough for a header.

CVSS v3
8.8
EG Score
8.8HIGHhigh confidence
EG Risk
40
EG Risk 40/100

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)
Severity88% × 45%
The EG Score, 8.8 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
41st
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

October 6, 2026

Last Modified

October 7, 2026

Advisory Details (6)

Auto-updated Oct 7, 2026
Patch available.
Web page

smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/05762c5bc1cfdcac36747994fde2c04387a457f1
Web page

smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/858d5ac22cb889266993e7670f9f0c4f4aeedd78
Web page

smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/96c436e4b010711452b2872558938f4ef276492a
Web page

smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8749946579708ea0d339034bb7f423a67dbe89cf
Web page

smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/491e33144dee872cffda207f6fcb09260728f803
Web page

smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/72eaef1f37a3b6bec11c342736834dc3707be3e4

Vendor Advisories for CVE-2026-98171(2)

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
linux6.1.106-1 ... 7.2~rc7-1~exp1 (360 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (183 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (181 versions)
  • every version up to 7.2.8-1: fixed in 7.2.8-1
—

Data Freshness Timeline

(refreshed 39× in last 7d / 50× 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.

  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  2. 2026-10-13 03:58 UTCEG score recompute
  3. 2026-10-13 03:58 UTCVendor advisory
  4. 2026-10-13 03:58 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  5. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  6. 2026-10-12 14:38 UTCEG score recompute
  7. 2026-10-12 03:22 UTCVendor advisory
  8. 2026-10-12 03:21 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  9. 2026-10-11 19:10 UTCEG score recompute
  10. 2026-10-11 16:25 UTCEG score recompute
  11. 2026-10-11 15:42 UTCEG score recompute
  12. 2026-10-11 15:42 UTCVendor advisory
  13. 2026-10-11 15:42 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  14. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  15. 2026-10-11 13:37 UTCEG score recompute
  16. 2026-10-11 04:08 UTCEG score recompute
  17. 2026-10-11 04:08 UTCVendor advisory
  18. 2026-10-11 04:08 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  19. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  20. 2026-10-10 16:33 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  21. 2026-10-10 04:57 UTCEG score recompute
  22. 2026-10-10 04:57 UTCVendor advisory
  23. 2026-10-10 04:57 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  24. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  25. 2026-10-09 17:24 UTCVendor advisory
Show 25 more
  1. 2026-10-09 17:23 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  2. 2026-10-09 05:46 UTCVendor advisory
  3. 2026-10-09 05:46 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  4. 2026-10-08 18:12 UTCEG score recompute
  5. 2026-10-08 18:12 UTCVendor advisory
  6. 2026-10-08 18:12 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  7. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  8. 2026-10-08 06:37 UTCEG score recompute
  9. 2026-10-08 06:37 UTCVendor advisory
  10. 2026-10-08 06:37 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  12. 2026-10-07 19:03 UTCEG score recompute
  13. 2026-10-07 19:03 UTCVendor advisory
  14. 2026-10-07 19:03 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf · GitHub severity HIGH · GitHub CVSS 8.8
  15. 2026-10-07 07:29 UTCEG score recompute
  16. 2026-10-07 07:29 UTCVendor advisory
  17. 2026-10-07 07:29 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf
  18. 2026-10-07 06:58 UTCEG score recomputeFirst assessed: 8.8 HIGH
  19. 2026-10-07 06:58 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf
  20. 2026-10-07 06:56 UTCMITRE cvelistV5CVSS v3 → 8.8 · severity → HIGH
  21. 2026-10-06 15:19 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  22. 2026-10-06 09:53 UTCGHSA enrichmentGHSA-68gh-wq6f-89rf
  23. 2026-10-06 09:28 UTCNVD update
  24. 2026-10-06 08:56 UTCEG score recompute
  25. 2026-10-06 08:52 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-98171?
CVE-2026-98171 is a high-severity vulnerability; its CVE record was published on October 6, 2026. In the Linux kernel, the following vulnerability has been resolved: smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs Fix several related bounds checking and pointer lifecycle issues in receiveencryptedstandard()'s handling of compound encrypted frames: Clear next_buffer…
When was the CVE record for CVE-2026-98171 published?
The CVE record for CVE-2026-98171 was published on October 6, 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 October 7, 2026; the record at its source may have been updated since.
Is CVE-2026-98171 actively exploited?
CVE-2026-98171 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (41st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-98171?
CVE-2026-98171 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-98171?
A fix for CVE-2026-98171 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-98171 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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