CVE-2026-98387

Uninitialized memory access via unchecked cipher-walk errors

Published Oct 14, 2026 · Updated Oct 14, 2026

Error handling in Linux s390 AES allows attackers to cause uninitialized memory access via failed cipher-walk initialization. In arch/s390/crypto/aes_s390.c, ecb_aes_crypt() and ctr_aes_crypt() process walk state without first checking skcipher_walk_virt() errors. Exposure requires the s390 implementation and a failed cipher walk; attacker privileges, a controllable trigger, and consequences beyond incorrect processing or uninitialized memory access are not published.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Get started

Summary

What happened

Error handling in Linux s390 AES allows attackers to cause uninitialized memory access via failed cipher-walk initialization. In arch/s390/crypto/aes_s390.c, ecb_aes_crypt() and ctr_aes_crypt() process walk state without first checking skcipher_walk_virt() errors. Exposure requires the s390 implementation and a failed cipher walk; attacker privileges, a controllable trigger, and consequences beyond incorrect processing or uninitialized memory access are not published.

The record

CVE
CVE-2026-98387
Published
Oct 14, 2026
Updated
Oct 14, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.5
  2. Affected versionversion=7988fb2c03c8cf9936f851ab19a6d21b3c3411c0 <15fa028589c3a2545f0bff355eff06d5844196bf
  3. Affected versionversion=7988fb2c03c8cf9936f851ab19a6d21b3c3411c0 <35c3f97569306050e818fa18e17fa97c358f0f28
  4. Affected versionversion=7988fb2c03c8cf9936f851ab19a6d21b3c3411c0 <89b58645646d1dac34162cc2597f42266bfbf930
  5. Affected versionversion=7988fb2c03c8cf9936f851ab19a6d21b3c3411c0 <aea3e1588f08e381a7a57b2bf1a60cc2347904cd

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=5.5; version=7988fb2c03c8cf9936f851ab19a6d21b3c3411c0 <15fa028589c3a2545f0bff355eff06d5844196bf; version=7988fb2c03c8cf9936f851ab19a6d21b3c3411c0 <35c3f97569306050e818fa18e17fa97c358f0f28; version=7988fb2c03c8cf9936f851ab19a6d21b3c3411c0 <89b58645646d1dac34162cc2597f42266bfbf930; version=7988fb2c03c8cf9936f851ab19a6d21b3c3411c0 <aea3e1588f08e381a7a57b2bf1a60cc2347904cd

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Get started to see how Hinoki identifies affected software and validates exploitability in your environment.

Get started