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CVE.org (no NVD analysis yet)· CNA Linux

CVE-2026-98403: s390/boot: Avoid IPL parameter append past command line

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.20% (FIRST EPSS).
  • Fixed version: Linux Linux 73eec5a0d55916d7e1115f5d03a7ffc06d6215cf, 8d11bfec8666f8409fac9072e9c25b691d3e30ac, af9866021a00ab9eeacf0c33ee73f3d134b4ed70.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 73eec5a0d55916d7e1115f5d03a7ffc06d6215cf, 8d11bfec8666f8409fac9072e9c25b691d3e30ac, af9866021a00ab9eeacf0c33ee73f3d134b4ed70 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

—No exploit Fix available
Published
Oct 14, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 10th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.16affected
    • 5ecb2da660ab8eddafe059a6a8a708465db89ca2 and later · before af9866021a00ab9eeacf0c33ee73f3d134b4ed70affected · git
    • 5ecb2da660ab8eddafe059a6a8a708465db89ca2 and later · before 73eec5a0d55916d7e1115f5d03a7ffc06d6215cfaffected · git
    • 5ecb2da660ab8eddafe059a6a8a708465db89ca2 and later · before 8d11bfec8666f8409fac9072e9c25b691d3e30acaffected · git
    • 5ecb2da660ab8eddafe059a6a8a708465db89ca2 and later · before d76181dfabdaa720703167393704efacba343442affected · git
    • before 5.16not affected · semver
    • 6.12.112 and later · up to and including 6.12.*not affected · semver
    • 6.18.53 and later · up to and including 6.18.*not affected · semver
    • 7.2.7 and later · up to and including 7.2.*not affected · semver
    • 7.3 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:12linux-6.12before 6.12.113-1~deb12u16.12.113-1~deb12u1
Debian:13linuxbefore 6.12.113-16.12.113-1
Debian:14linuxbefore 7.2.7-17.2.7-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-98401Oct 14, 2026 · net: iptunnel: fix stale transport header during tunnel decapsulation
    30Monitor
  • ← EarlierCVE-2026-98402Oct 14, 2026 · net: icmp: avoid invalid transport header access in icmp_send tracepoint
    0Monitor
  • Later →CVE-2026-98404Oct 14, 2026 · drm/virtio: Fix a NULL vs ERR_PTR() bug in virtio_gpu_user_framebuffer_create()
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux73eec5a0d55916d7e1115f5d03a7ffc06d6215cfVendor (CNA)
Linux Linux8d11bfec8666f8409fac9072e9c25b691d3e30acVendor (CNA)
Linux Linuxaf9866021a00ab9eeacf0c33ee73f3d134b4ed70Vendor (CNA)
Linux Linuxd76181dfabdaa720703167393704efacba343442Vendor (CNA)
debian:linux6.12.113-1 · Debian:13Package registry (OSV)
debian:linux7.2.7-1 · Debian:14Package registry (OSV)
debian:linux-6.126.12.113-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 5, 2026+22 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Exploit maturity— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records