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TI-2026-73934 Aliases CVE-2026-98403GHSA-7qjr-375p-687v

Out-of-bounds write in Linux kernel s390 boot IPL parameter handling

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 fixed, 5 without a fix

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

Summary

In the Linux kernel from 5.16, the s390 boot code appends an IPL parameter past the end of the command line buffer. When the command line fills all but the terminating byte, the conversion helpers receive a zero size and write one byte past the buffer.

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: s390/boot: Avoid IPL parameter append past command line A command line may occupy all but the terminating byte of COMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size to the IPL parameter conversion helpers and points the destination one byte past early_command_line. The helpers subtract one from the unsigned size and write the converted parameter outside the command line buffer. Convert the IPL parameter in the command line parsing buffer first. A parameter beginning with '=' can then replace the existing command line regardless of its length, while other parameters are appended only when space remains.

Why it matters now

EPSS 0.00206 10th percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.12.112, 6.18.53, 7.2.7 +1Red Hat: 1 advisoryRed Hat: 5 fixed, 5 without a fix

SSVC decision points

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

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux5.16 and later6.12.112, 6.18.53, 7.2.7, 7.3Patch availableCNA
  • Linux VendorLinux Affected 5.16 and later Fixed in 6.12.112, 6.18.53, 7.2.7, 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

Update the Linux kernel to 6.12.112, 6.18.53, 7.2.7 or 7.3. Red Hat fixes Red Hat Enterprise Linux 9 AppStream, BaseOS, CodeReady Linux Builder, Real Time and Real Time for NFV in RHSA-2026:95370. The sources list no fixed version for Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 10, Red Hat OpenShift Container Platform 4 and Red Hat OpenShift Container Platform 5.

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

  • Fix · CNA Linux (Linux) Fixed in 6.12.112, 6.18.53, 7.2.7, 7.3

Red Hat 1 advisory

  • RHSA-2026:95370 Released 2026-11-05 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.66.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.66.1.el9_8, kernel-64k-devel-5.14.0-687.66.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.66.1.el9_8, kernel-64k-5.14.0-687.66.1.el9_8, kernel-64k-core-5.14.0-687.66.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.66.1.el9_8, libperf-5.14.0-687.66.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.66.1.el9_8, kernel-rt-64k-5.14.0-687.66.1.el9_8, kernel-rt-64k-core-5.14.0-687.66.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.66.1.el9_8, kernel-rt-core-5.14.0-687.66.1.el9_8, kernel-rt-debug-5.14.0-687.66.1.el9_8 +9

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
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 5AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:95370
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:95370
Not affected: 3 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat OpenShift Container Platform 4

Timeline

  1. 2026-10-14 Threatist record created from CVE-2026-98403
  2. 2026-10-14 Alias added: GHSA-7qjr-375p-687v
  3. 2026-10-16 Affected versions changed · Red Hat
  4. 2026-10-16 CVSS score added · Red Hat
  5. 2026-10-19 Fix available: Linux/[email protected] · CNA
  6. 2026-10-27 CVSS score changed · Red Hat
  7. 2026-10-30 Affected versions changed · Red Hat
  8. 2026-11-06 Fix available: RHSA-2026:95370 · Red Hat
  9. 2026-11-06 Fix available: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) +2 · Red Hat

References

Other 4

  • 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