CVE-2026-80550
s390/vfio_ccw: Fix out of bounds check on CCW array
Description
In the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Fix out of bounds check on CCW array The routine ccwchain_calc_length() counts the number of channel command words (CCWs) that are chained together in a single channel program, and rejects anything larger than CCWCHAIN_LEN_MAX (256) CCWs. The loop itself is "do..while (count < 257)", and while the logic in is_cpa_within_range() correctly adjusts between the 0-index array of CCWs and the count of CCWs starting at 1, this means it would look at a possible 257th CCW before ending the loop and (correctly) returning an error. Fix this by restructuring the loop to break as soon as 256 CCWs (thus indexes 0-255) are examined, without looking at memory outside the range.
INFO
Published Date :
Aug. 26, 2026, 3:17 p.m.
Last Modified :
Aug. 26, 2026, 3:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-80550
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the Linux kernel to the latest version.
- Apply the patch for the vfio_ccw component.
- Verify the fix by testing CCW chain length validation.
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-2026-80550.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-80550 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-2026-80550
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).
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The following list is the news that have been mention
CVE-2026-80550 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-80550 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.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 26, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Fix out of bounds check on CCW array The routine ccwchain_calc_length() counts the number of channel command words (CCWs) that are chained together in a single channel program, and rejects anything larger than CCWCHAIN_LEN_MAX (256) CCWs. The loop itself is "do..while (count < 257)", and while the logic in is_cpa_within_range() correctly adjusts between the 0-index array of CCWs and the count of CCWs starting at 1, this means it would look at a possible 257th CCW before ending the loop and (correctly) returning an error. Fix this by restructuring the loop to break as soon as 256 CCWs (thus indexes 0-255) are examined, without looking at memory outside the range. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80550.json">CVE-2026-80550</a> Added Reference https://git.kernel.org/stable/c/0282fb1c4b638eecfe2cc558092c460911d8f7e2 Added Reference https://git.kernel.org/stable/c/499a8a66b1598bfab97182aed15e0f1646074a3d Added Reference https://git.kernel.org/stable/c/4c2e1d359d7a2b82cdf3254e4e480af9417f99fb Added Reference https://git.kernel.org/stable/c/907adc667d902fafbdb2d740d57b55bd025dc4cd Added Reference https://git.kernel.org/stable/c/a005b7f1a491ffda61bff0fd0f6548f8986fb977 Added Reference https://git.kernel.org/stable/c/af3f80ca4c8b17f20f9e588def076288fdb49e65 Added Reference https://git.kernel.org/stable/c/d5d096cd9369e986d4e5153baa86b8b35c283e09 Added Reference https://git.kernel.org/stable/c/f20be33d093ce7630c17ff7ed93caf7eaf8ac1a3