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TI-2026-75577 Aliases CVE-2026-98449GHSA-2758-q84j-4rxj

Linux kernel SMB client mishandles compound requests on send failure

Priority LOW 22Published · Updated

Key facts

Attack vector
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Privileges required
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User interaction
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Attack complexity
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Impact type
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Confidentiality · integrity · availability
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Fix status
Partial Red Hat: 5 without a fix

No CVSS vector from any source. Fix status from CNA and Red Hat.

Summary

The Linux kernel SMB client is affected in ranges from 4.20.11 before 4.21 and from 5.0. When sending a compound request fails, the client leaves the requests on its pending list before unlocking the server, so a reconnect returns their credits and then returns them again, decrementing the in-flight count twice. The flaw is triggered when a socket send fails during SMB2 negotiation, and it causes a kernel warning in smb2_add_credits().

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

In the Linux kernel, the following vulnerability has been resolved: smb: client: delete compound mids on send failure before unlock When sending a compound request fails, smb_send_rqst() kicks off a reconnect. compound_send_recv() still has those mids on pending_mid_q, but it unlocks the server without removing them first. During reconnect, cifs_abort_connection() walks pending_mid_q and runs each mid callback. With no response yet, those callbacks return credits and drop in_flight. Then compound_send_recv()'s send-error path returns the same credits again. in_flight ends up decremented twice and smb2_add_credits() WARNs. syzbot hits this during SMB2_negotiate when the socket send fails. cifs_call_async() already calls delete_mid() before unlock on send failure. Do the same for compound chains and set cancelled_mid[] so the out: path does not delete them again.

Why it matters now

EPSS 0.00173 6th percentileScored 2026-11-07
Fix Partial Linux (Linux): 4.21, 6.18.61, 7.2.9 +1Red Hat: 5 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux4.20.11 to before 4.214.21Patch availableCNA
LinuxLinux5.0 and later6.18.61, 7.2.9, 7.3Patch availableCNA
  • Linux VendorLinux Affected 4.20.11 to before 4.21 Fixed in 4.21 Patch available CNA
  • Linux VendorLinux Affected 5.0 and later Fixed in 6.18.61, 7.2.9, 7.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

Upgrade to Linux kernel 4.21 or to a commit that fixes it: 59d30bdc3dd6fd3a8990f59bc7a137b1cbb3ed4e, 70783946f3b5d0c06ec7df0f5e7bec2bfad24efb or 8f6f8a48399f82f4a83f7b9f25b9707e0062a4f9, or upgrade to 6.18.61, 7.2.9 or 7.3. Red Hat lists no available fix for Red Hat Enterprise Linux 8, 9 and 10 and for Red Hat OpenShift Container Platform 4 and 5.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA Linux (Linux) Fixed in 4.21
  • Fix · CNA Linux (Linux) Fixed in 6.18.61, 7.2.9, 7.3

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-18 Threatist record created from CVE-2026-98449
  2. 2026-10-18 Alias added: GHSA-2758-q84j-4rxj
  3. 2026-10-19 Fix available: Linux/[email protected] · CNA
  4. 2026-10-20 Affected versions changed · Red Hat
  5. 2026-10-20 CVSS score added · Red Hat
  6. 2026-10-30 Affected versions changed · Red Hat
  7. 2026-11-06 Fix available: Linux/Linux@59d30bdc3dd6fd3a8990f59bc7a137b1cbb3ed4e, Linux/[email protected] · CNA
  8. 2026-11-06 1 new reference · CNA

References

Other 3

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences