CVE-2026-52933
io_uring/poll: fix signed comparison in io_poll_get_ownership()
Description
In the Linux kernel, the following vulnerability has been resolved: io_uring/poll: fix signed comparison in io_poll_get_ownership() io_poll_get_ownership() uses a signed comparison to check whether poll_refs has reached the threshold for the slowpath: if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG (BIT(31)) is set in poll_refs, the value becomes negative in signed arithmetic, so the >= 128 comparison always evaluates to false and the slowpath is never taken. Fix this by casting the atomic_read() result to unsigned int before the comparison, so that the cancel flag is treated as a large positive value and correctly triggers the slowpath.
INFO
Published Date :
June 24, 2026, 8:16 a.m.
Last Modified :
July 8, 2026, 3:28 p.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
- Update the Linux kernel.
- Apply the patch for io_uring/poll.
- Ensure atomic_read results are unsigned.
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-2026-52933.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-52933 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-2026-52933
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-2026-52933 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-52933 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.
-
Initial Analysis by [email protected]
Jul. 08, 2026
Action Type Old Value New Value Added CWE CWE-835 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:6.1:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.1:rc8:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.1:-:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.0.11 up to (excluding) 6.1 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.86 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.140 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.1.1 up to (excluding) 6.1.175 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.27 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.4 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.15.82 up to (excluding) 5.16 Added Reference Type kernel.org: https://git.kernel.org/stable/c/326941b22806cbf2df1fbfe902b7908b368cce42 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/81bf96b0abbfa4cd47ea32e12596aed3855fb2f3 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c6d191164dc81838d8dbf452a6000f68c558d1ae Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/cf522703d4f194991615763697ae25a3f9539763 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/ea0697129807d718037f618221037aa0660ee3c5 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/fc47043f3d9af3efa407665b47f8378ec691ba18 Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 28, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 24, 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': 'a26a35e9019fd70bf3cf647dcfdae87abc7bacea', 'lessThan': '81bf96b0abbfa4cd47ea32e12596aed3855fb2f3', 'versionType': 'git'}, {'status': 'affected', 'version': 'a26a35e9019fd70bf3cf647dcfdae87abc7bacea', 'lessThan': 'cf522703d4f194991615763697ae25a3f9539763', 'versionType': 'git'}, {'status': 'affected', 'version': 'a26a35e9019fd70bf3cf647dcfdae87abc7bacea', 'lessThan': 'fc47043f3d9af3efa407665b47f8378ec691ba18', 'versionType': 'git'}, {'status': 'affected', 'version': 'a26a35e9019fd70bf3cf647dcfdae87abc7bacea', 'lessThan': 'ea0697129807d718037f618221037aa0660ee3c5', 'versionType': 'git'}, {'status': 'affected', 'version': 'a26a35e9019fd70bf3cf647dcfdae87abc7bacea', 'lessThan': 'c6d191164dc81838d8dbf452a6000f68c558d1ae', 'versionType': 'git'}, {'status': 'affected', 'version': 'a26a35e9019fd70bf3cf647dcfdae87abc7bacea', 'lessThan': '326941b22806cbf2df1fbfe902b7908b368cce42', 'versionType': 'git'}, {'status': 'affected', 'version': '4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048', 'versionType': 'git'}, {'status': 'affected', 'version': 'bc4e6ee16778149811333a969a7a893d4cc110c5', 'versionType': 'git'}, {'status': 'affected', 'version': '5.15.82', 'lessThan': '5.16', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.0.11', 'lessThan': '6.1', 'versionType': 'semver'}], 'programFiles': ['io_uring/poll.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.1'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.1', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.175', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.140', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.86', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.27', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.4', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['io_uring/poll.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: io_uring/poll: fix signed comparison in io_poll_get_ownership() io_poll_get_ownership() uses a signed comparison to check whether poll_refs has reached the threshold for the slowpath: if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG (BIT(31)) is set in poll_refs, the value becomes negative in signed arithmetic, so the >= 128 comparison always evaluates to false and the slowpath is never taken. Fix this by casting the atomic_read() result to unsigned int before the comparison, so that the cancel flag is treated as a large positive value and correctly triggers the slowpath. Added Reference https://git.kernel.org/stable/c/326941b22806cbf2df1fbfe902b7908b368cce42 Added Reference https://git.kernel.org/stable/c/81bf96b0abbfa4cd47ea32e12596aed3855fb2f3 Added Reference https://git.kernel.org/stable/c/c6d191164dc81838d8dbf452a6000f68c558d1ae Added Reference https://git.kernel.org/stable/c/cf522703d4f194991615763697ae25a3f9539763 Added Reference https://git.kernel.org/stable/c/ea0697129807d718037f618221037aa0660ee3c5 Added Reference https://git.kernel.org/stable/c/fc47043f3d9af3efa407665b47f8378ec691ba18