Linux Kernel up to 6.12.96/6.18.38/7.1.3 s390 load_unaligned_zeropad infinite loop

CVSS Meta Temp Score
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CTI Interest Score
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6.0$0-$5k3.11-

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.12.96/6.18.38/7.1.3. Affected by this vulnerability is the function load_unaligned_zeropad of the component s390. Performing a manipulation results in infinite loop. This vulnerability was named CVE-2026-64369. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.96/6.18.38/7.1.3. It has been classified as critical. This affects the function load_unaligned_zeropad of the component s390. The manipulation with an unknown input leads to a infinite loop vulnerability. CWE is classifying the issue as CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: s390: Revert support for DCACHE_WORD_ACCESS load_unaligned_zeropad() reads eight bytes from unaligned addresses and may cross page boundaries. It handles exceptions which may happen if reading from the second page results in an exception. For pages which are donated to the Ultravisor for secure execution purposes the do_secure_storage_access() exception handler however does not handle such exceptions correctly. Such an exception may result in an endless exception loop which will never be resolved. An attempt to fix this [1] turned out to be not sufficient. For now revert load_unaligned_zeropad() until this problem has been resolved in a proper way. Note that the implementation of load_unaligned_zeropad() itself is correct. The revert is just a temporary workaround until there is complete fix for secure storage access exceptions. [1] commit b00be77302d7 ("s390/mm: Add missing secure storage access fixups for donated memory")

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-64369 since 07/19/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/25/2026). The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 6.12.97, 6.18.39, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch c9e0f1517631ac08987f8385817119bccf2f1f12/be79d285bea70d0edd5015bd487311bfa8cbebc9/c94806905e02cc8e17a69c822d93c41743b7ffc5/37540b8c287fc817bdbd0c62bb75ad6eab0e5d03 is able to eliminate this problem.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Infinite loop
CWE: CWE-835 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.97/6.18.39/7.1.4/7.2-rc1
Patch: c9e0f1517631ac08987f8385817119bccf2f1f12/be79d285bea70d0edd5015bd487311bfa8cbebc9/c94806905e02cc8e17a69c822d93c41743b7ffc5/37540b8c287fc817bdbd0c62bb75ad6eab0e5d03

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64369 (🔒)
GCVE (CVE): GCVE-0-2026-64369
GCVE (VulDB): GCVE-100-383163

Entryinfo

Created: 07/25/2026 17:28
Changes: 07/25/2026 17:28 (59)
Complete: 🔍
Cache ID: 216::103

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