Skip to content

CVE-2026-45856

Out-of-bounds Read: is CVE-2026-45856real, exploitable, or a false positive? Here's the community verdict.

signals

public sources

Exploited in wild
Not listed
CISA KEV
Base severity
7.1 High
CVSS
Exploitation prob.
0.2%
FIRST EPSS
Weakness
CWE-125 · Out-of-bounds Read
CWE

High CVSS base score, but low real-world exploitation probability (EPSS). Likely less urgent than the score implies.

baseline read

auto · not a community verdict

Real, but low real-world risk

A genuine vulnerability on paper, but EPSS shows little real-world exploitation — the base score may overstate urgency. This is not the same as a false positive.

Based on CVSS · FIRST EPSS

Confirm or dispute →
Affected:Linux

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

In the Linux kernel, the following vulnerability has been resolved: RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send ib_uverbs_post_send() uses cmd.wqe_size from userspace without any validation before passing it to kmalloc() and using the allocated buffer as struct ib_uverbs_send_wr. If a user provides a small wqe_size value (e.g., 1), kmalloc() will succeed, but subsequent accesses to user_wr->opcode, user_wr->num_sge, and other fields will read beyond the allocated buffer, resulting in an out-of-bounds read from kernel heap memory. This could potentially leak sensitive kernel information to userspace. Additionally, providing an excessively large wqe_size can trigger a WARNING in the memory allocation path, as reported by syzkaller. This is inconsistent with ib_uverbs_unmarshall_recv() which properly validates that wqe_size >= sizeof(struct ib_uverbs_recv_wr) before proceeding. Add the same validation for ib_uverbs_post_send() to ensure wqe_size is at least sizeof(struct ib_uverbs_send_wr).

Published

Embed this verdict
TruePositive verdict for CVE-2026-45856
Markdown
[![TruePositive verdict](https://www.truepositive.app/cve/CVE-2026-45856/badge.svg)](https://www.truepositive.app/cve/CVE-2026-45856)
HTML
<a href="https://www.truepositive.app/cve/CVE-2026-45856"><img src="https://www.truepositive.app/cve/CVE-2026-45856/badge.svg" alt="TruePositive verdict for CVE-2026-45856"></a>

Live badge that updates automatically as the community verdict changes.

Community ground truth

Be the first practitioner to weigh in

So far this is only TruePositive's editorial baseline from public sources. Add your real-world verdict below — it becomes the signal the next person triaging this relies on.

🥇 The first 50 practitioners to contribute earn a Founding Contributor badge.

In your experience, is this finding real and exploitable?

0 verdicts
Not a real issue

No account needed. Anonymous verdicts post as an unverified signal. Log in to make yours verified and earn reputation.

Field notes & remediation

Verdicts are the quick signal. Notes are the evidence and fixes behind them.

No notes yet. Be the first to share what you saw, or a fix that worked.

    Add a field note or remediationoptional
    Note type

    What are you adding?

    Markdown supported · minimum 20 characters.

    Same weakness: CWE-125 · Out-of-bounds Read.