CVE-2026-68453
s390/zcrypt: Fix buffer over-read in cca_cipher2protkey
Description
In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Fix buffer over-read in cca_cipher2protkey Add validation of both the actual key buffer size and token length fields in all the cca_check_sec*token() functions. Additionally check in cca_gencipherkey() for possible underflow with returned key size. The CCA token structures contain user-controlled len fields that were used in operations without proper validation against both the actual buffer size and minimum token structure size. An attacker could set this field larger than the actual buffer size, leading to reading beyond buffer boundaries. This may result in a kernel crash or exposure of memory via sending this as part of a request down to the crypto card. Also an attacker could have used a very small len value and thus enforce a buffer under-run which may produce similar effects as a over-read. So now a key must - key buf length must be at least sizeof the token struct - the key len field inside the token must fit into the range of sizeof key token struct ... key buf length
INFO
Published Date :
Aug. 13, 2026, 3:19 p.m.
Last Modified :
Aug. 17, 2026, 6:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Validate key buffer size and token length fields.
- Check for underflow with returned key size.
- Ensure key length fits within bounds.
- Apply the security update for the Linux kernel.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-68453.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-68453 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-68453
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-68453 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-68453 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd', 'lessThan': 'a57fd7fcdb63e2d5ceac78bbe825ec986062a9da', 'versionType': 'git'}, {'status': 'affected', 'version': '4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd', 'lessThan': '3b2abee2a678607ae27975bc6833785c2002df43', 'versionType': 'git'}, {'status': 'affected', 'version': '4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd', 'lessThan': '36b230835b8a008266aad22168ca52afacc8a58d', 'versionType': 'git'}], 'programFiles': ['drivers/s390/crypto/pkey_cca.c', 'drivers/s390/crypto/zcrypt_ccamisc.c', 'drivers/s390/crypto/zcrypt_ccamisc.h'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.4'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.4', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.44', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.8', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc6', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/s390/crypto/pkey_cca.c', 'drivers/s390/crypto/zcrypt_ccamisc.c', 'drivers/s390/crypto/zcrypt_ccamisc.h'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd', 'lessThan': 'a57fd7fcdb63e2d5ceac78bbe825ec986062a9da', 'versionType': 'git'}, {'status': 'affected', 'version': '4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd', 'lessThan': '3b2abee2a678607ae27975bc6833785c2002df43', 'versionType': 'git'}, {'status': 'affected', 'version': '4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd', 'lessThan': '36b230835b8a008266aad22168ca52afacc8a58d', 'versionType': 'git'}], 'programFiles': ['drivers/s390/crypto/pkey_cca.c', 'drivers/s390/crypto/zcrypt_ccamisc.c', 'drivers/s390/crypto/zcrypt_ccamisc.h'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.4'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.4', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.44', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.8', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/s390/crypto/pkey_cca.c', 'drivers/s390/crypto/zcrypt_ccamisc.c', 'drivers/s390/crypto/zcrypt_ccamisc.h'], 'defaultStatus': 'affected'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 13, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd', 'lessThan': 'a57fd7fcdb63e2d5ceac78bbe825ec986062a9da', 'versionType': 'git'}, {'status': 'affected', 'version': '4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd', 'lessThan': '3b2abee2a678607ae27975bc6833785c2002df43', 'versionType': 'git'}, {'status': 'affected', 'version': '4bc123b18ce6ae6c42c69d0456b5acbd2f7bc8bd', 'lessThan': '36b230835b8a008266aad22168ca52afacc8a58d', 'versionType': 'git'}], 'programFiles': ['drivers/s390/crypto/pkey_cca.c', 'drivers/s390/crypto/zcrypt_ccamisc.c', 'drivers/s390/crypto/zcrypt_ccamisc.h'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.4'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.4', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.44', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.8', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc6', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/s390/crypto/pkey_cca.c', 'drivers/s390/crypto/zcrypt_ccamisc.c', 'drivers/s390/crypto/zcrypt_ccamisc.h'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Fix buffer over-read in cca_cipher2protkey Add validation of both the actual key buffer size and token length fields in all the cca_check_sec*token() functions. Additionally check in cca_gencipherkey() for possible underflow with returned key size. The CCA token structures contain user-controlled len fields that were used in operations without proper validation against both the actual buffer size and minimum token structure size. An attacker could set this field larger than the actual buffer size, leading to reading beyond buffer boundaries. This may result in a kernel crash or exposure of memory via sending this as part of a request down to the crypto card. Also an attacker could have used a very small len value and thus enforce a buffer under-run which may produce similar effects as a over-read. So now a key must - key buf length must be at least sizeof the token struct - the key len field inside the token must fit into the range of sizeof key token struct ... key buf length Added Reference https://git.kernel.org/stable/c/36b230835b8a008266aad22168ca52afacc8a58d Added Reference https://git.kernel.org/stable/c/3b2abee2a678607ae27975bc6833785c2002df43 Added Reference https://git.kernel.org/stable/c/a57fd7fcdb63e2d5ceac78bbe825ec986062a9da