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NVD / CVE Program· CNA Linux

CVE-2026-90209: s390/debug: Fix deadlock during unregister

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: 0.21% (FIRST EPSS).
  • Fixed version: Linux Linux 183f8f6d64bb0510070c856b9927618c53014a7b, 445c31ac638fd1af203d79bdf25fc0cb3149fbbc, 45bb341d1b73eb293e0dd43d9b72bbc8b615d0ba.

Low priority for now. Upgrade to Linux Linux 183f8f6d64bb0510070c856b9927618c53014a7b, 445c31ac638fd1af203d79bdf25fc0cb3149fbbc, 45bb341d1b73eb293e0dd43d9b72bbc8b615d0ba 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/debug: Fix deadlock during unregister Unregistering an s390dbf debug area while one of the associated debugfs files is being written to can cause a deadlock: $ echo >.../vmur/level $ rmmod vmur =================================================== debugfs write debugfs_file_get() debug_unregister() mutex_lock(debug_mutex) debugfs_remove() wait for debugfs_file_put() debug_file_ops.write() debug_input() mutex_lock(debug_mutex) ==> DEADLOCK Fix this by splitting debug_unregister() into an s390dbf and debugfs part, and running only the s390dbf part with debug_mutex locked.

—No exploit Fix available
Published
Sep 17, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 11th 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 exploit code appears or is weaponized
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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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

    • c68ba4a708fbd0efdc384cd29250bb292a45e559, 86f9980909f31ab205323eeeb290fe3cbb4952b4, fe5793e90d3f572a87ba67fe2f0e1679fdff14f8, e234f66168f0d50c0d28154fb983a14e85c3c526, 5.15affected
    • 9372a82892c2caa6bccab9a4081166fa769699f8 and later · before a214c3dacc779b2afcb0ac9c8001e45ee4ffb2edaffected · git
    • 9372a82892c2caa6bccab9a4081166fa769699f8 and later · before 183f8f6d64bb0510070c856b9927618c53014a7baffected · git
    • 9372a82892c2caa6bccab9a4081166fa769699f8 and later · before a08b70ed2d1ec907353a72f15163b8e34ff4b2f8affected · git
    • 9372a82892c2caa6bccab9a4081166fa769699f8 and later · before 45bb341d1b73eb293e0dd43d9b72bbc8b615d0baaffected · git
    • 9372a82892c2caa6bccab9a4081166fa769699f8 and later · before 5d83f3faa3fb7f23f298cfd40382611999de5d1daffected · git
    • 9372a82892c2caa6bccab9a4081166fa769699f8 and later · before 54e1259b75d6402a1d0cfb822b9bb2c507e53dabaffected · git
    • 9372a82892c2caa6bccab9a4081166fa769699f8 and later · before 445c31ac638fd1af203d79bdf25fc0cb3149fbbcaffected · git
    • 5.4.146 and later · before 5.5affected · semver
    • 5.10.65 and later · before 5.11affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

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-2026-90207Sep 17, 2026 · ALSA: seq: midi: Serialize input teardown with event_input
    31Monitor
  • ← EarlierCVE-2026-90208Sep 17, 2026 · clocksource/drivers/samsung_pwm: Switch to raw_spinlock_t type
    0Monitor
  • Later →CVE-2026-90210Sep 17, 2026 · bpf: Fix UAF in bpf_trampoline_multi_attach_free on update failure
    31Monitor

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 Linux183f8f6d64bb0510070c856b9927618c53014a7bVendor (CNA)
Linux Linux445c31ac638fd1af203d79bdf25fc0cb3149fbbcVendor (CNA)
Linux Linux45bb341d1b73eb293e0dd43d9b72bbc8b615d0baVendor (CNA)
Linux Linux5.11Vendor (CNA)
Linux Linux5.14Vendor (CNA)
Linux Linux5.15Vendor (CNA)
Linux Linux5.5Vendor (CNA)
Linux Linux54e1259b75d6402a1d0cfb822b9bb2c507e53dabVendor (CNA)
Linux Linux5d83f3faa3fb7f23f298cfd40382611999de5d1dVendor (CNA)
Linux Linuxa08b70ed2d1ec907353a72f15163b8e34ff4b2f8Vendor (CNA)
Linux Linuxa214c3dacc779b2afcb0ac9c8001e45ee4ffb2edVendor (CNA)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~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.

No dated events beyond publication.

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.

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Bug bounty scope

No known public program.

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

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. Fix✗ → ✓

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References

Show all references (6 more)

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

All records