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Linux KernelOperating system · Linux

CVE-2026-53038

MEDIUM · 5.5 CVSS v3.1 Published 2026-06-24
Fix available
A fix is available. Upgrade to 6.12.91 / 6.18.33 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: ima_fs: Correctly create securityfs files for unsupported hash algos ima_tpm_chip->allocated_banks[i].crypto_id is initialized to HASH_ALGO__LAST if the TPM algorithm is not supported. However there are places relying on the algorithm to be valid because it is accessed by hash_algo_name[]. On 6.12.40 I observe the following read out-of-bounds in hash_algo_name: ================================================================== BUG: KASAN: global-out-of-bounds in create_securityfs_measurement_lists+0x396/0x440 Read of size 8 at addr ffffffff83e18138 by task swapper/0/1 CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.40 #3 Call Trace: <TASK> dump_stack_lvl+0x61/0x90 print_report+0xc4/0x580 ? kasan_addr_to_slab+0x26/0x80 ? create_securityfs_measurement_lists+0x396/0x440 kasan_report+0xc2/0x100 ? create_securityfs_measurement_lists+0x396/0x440 create_securityfs_measurement_lists+0x396/0x440 ima_fs_init+0xa3/0x300 ima_init+0x7d/0xd0 init_ima+0x28/0x100 do_one_initcall+0xa6/0x3e0 kernel_init_freeable+0x455/0x740 kernel_init+0x24/0x1d0 ret_from_fork+0x38/0x80 ret_from_fork_asm+0x11/0x20 </TASK> The buggy address belongs to the variable: hash_algo_name+0xb8/0x420 Memory state around the buggy address: ffffffff83e18000: 00 01 f9 f9 f9 f9 f9 f9 00 01 f9 f9 f9 f9 f9 f9 ffffffff83e18080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffffff83e18100: 00 00 00 00 00 00 00 f9 f9 f9 f9 f9 00 05 f9 f9 ^ ffffffff83e18180: f9 f9 f9 f9 00 00 00 00 00 00 00 04 f9 f9 f9 f9 ffffffff83e18200: 00 00 00 00 00 00 00 00 04 f9 f9 f9 f9 f9 f9 f9 ================================================================== Seems like the TPM chip supports sha3_256, which isn't yet in tpm_algorithms: tpm tpm0: TPM with unsupported bank algorithm 0x0027 That's TPM_ALG_SHA3_256 == 0x0027 from "Trusted Platform Module 2.0 Library Part 2: Structures", page 51 [1]. See also the related U-Boot algorithms update [2]. Thus solve the problem by creating a file name with "_tpm_alg_<ID>" postfix if the crypto algorithm isn't initialized. This is how it looks on the test machine (patch ported to v6.12 release): # ls -1 /sys/kernel/security/ima/ ascii_runtime_measurements ascii_runtime_measurements_tpm_alg_27 ascii_runtime_measurements_sha1 ascii_runtime_measurements_sha256 binary_runtime_measurements binary_runtime_measurements_tpm_alg_27 binary_runtime_measurements_sha1 binary_runtime_measurements_sha256 policy runtime_measurements_count violations [1]: https://trustedcomputinggroup.org/wp-content/uploads/Trusted-Platform-Module-2.0-Library-Part-2-Version-184_pub.pdf [2]: https://lists.denx.de/pipermail/u-boot/2024-July/558835.html

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In the Linux kernel's IMA (Integrity Measurement Architecture) subsystem, when a TPM chip supports algorithms not in the supported tpm_algorithms list (e.g., sha3_256 with ID 0x0027), the crypto_id is set to HASH_ALGO__LAST. This invalid index is then used to access hash_algo_name[], causing a global out-of-bounds read in create_securityfs_measurement_lists. The fix creates file names with '_tpm_alg_<ID>' postfix for unsupported crypto algorithms instead of using the invalid hash_algo_name index.

MitigationThis kernel bug requires a code fix in the IMA subsystem to properly handle unsupported TPM algorithms by using the raw TPM algorithm ID in the filename rather than an invalid hash algorithm index. System administrators should monitor for the 'TPM with unsupported bank algorithm' message and apply the kernel patch when available.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 6.10, < 6.12.91>= 6.13, < 6.18.33>= 6.19, < 7.0.10

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check kernel version against affected ranges
    Run 'uname -r' or 'cat /proc/version' and compare to the affected versions: >= 6.10 < 6.12.91, >= 6.13 < 6.18.33, or >= 6.19 < 7.0.10
    Affected if Kernel version falls within any of the affected version ranges
  2. Verify IMA is enabled
    Check if /sys/kernel/security/ima exists, or run 'cat /proc/cmdline' and look for 'ima' or 'ima_template' in boot parameters
    Affected if IMA is active and measuring files (the vulnerable code path is only exercised when IMA is running)
  3. Check for TPM hardware presence
    Look for TPM device files: 'ls /dev/tpm*' or check 'cat /sys/class/tpm/tpm0/algorithm'
    Affected if A TPM chip is present in the system
  4. Look for unsupported TPM algorithm log messages
    Run 'dmesg | grep -i "TPM"' or check /var/log/kern.log for messages containing 'TPM with unsupported bank algorithm' or similar warnings about unsupported TPM algorithms
    Affected if Logs show messages about TPM using algorithms not in the supported tpm_algorithms list (e.g., sha3_256 or algorithm ID 0x0027)
  5. Verify IMA runtime policies are active
    Check /sys/kernel/security/ima/policy or run 'ima_policy' tool to see if measurement rules are loaded and active
    Affected if IMA policies are loaded and actively performing measurements, which triggers the vulnerable create_securityfs_measurement_lists function

A system is affected if it runs a vulnerable kernel version AND has IMA enabled with a TPM that supports algorithms outside the kernel's supported list, as indicated by kernel logs about unsupported TPM bank algorithms.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.12.91 / 6.18.33 / 7.0.10 or later
Fixed in 6.12.916.18.337.0.10
Interim mitigation

This kernel bug requires a code fix in the IMA subsystem to properly handle unsupported TPM algorithms by using the raw TPM algorithm ID in the filename rather than an invalid hash algorithm index. System administrators should monitor for the 'TPM with unsupported bank algorithm' message and apply the kernel patch when available.

Recommended fix High confidence

Upgrade to kernel 6.12.91+, 6.18.33+, or 7.0.10+ depending on which branch you are on

  1. Identify the current running kernel version using `uname -r`
  2. Confirm the kernel version falls within one of the affected ranges: >= 6.10 and < 6.12.91, >= 6.13 and < 6.18.33, or >= 6.19 and < 7.0.10
  3. Upgrade the kernel to a patched version: 6.12.91 or later, 6.18.33 or later, or 7.0.10 or later
  4. Reboot the system to load the fixed kernel
  5. Verify the upgrade by checking `uname -r` shows a version >= the fixed version for your branch
  6. Optionally verify the fix by checking `/sys/kernel/security/ima/` - files for unsupported TPM algorithms should now use naming like `*_tpm_alg_27` instead of causing an out-of-bounds read
Caveat Standard kernel upgrade risks apply - ensure compatibility with local kernel modules and system configuration before upgrading production systems

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53038 in production — separate from our analysis above.

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What this is

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What belongs here
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