Bug 2520161 (CVE-2026-18917) - CVE-2026-18917 libvirt: Integer overflow in NodeGetFreePages RPC handler leading to heap buffer overflow
Summary: CVE-2026-18917 libvirt: Integer overflow in NodeGetFreePages RPC handler lead...
Keywords:
Status: NEW
Alias: CVE-2026-18917
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2520165
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-20 09:04 UTC by OSIDB Bzimport
Modified: 2026-08-20 09:33 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-08-20 09:04:51 UTC
An integer overflow vulnerability was found in libvirt's NodeGetFreePages RPC handler in src/remote/remote_daemon_dispatch.c. The dispatcher computes a 32-bit product (pages_len * cellCount) for both validation and memory allocation. While pages_len is XDR-capped at 1024, cellCount remains unbounded. The multiplication truncates modulo 2^32, allowing crafted values to bypass the guard check. The undersized buffer is then overwritten with real NUMA node data. The RPC call requires only connect:read ACL (lowest permission tier) and is accessible via the world-readable Unix socket (mode 0666) with no authentication for VIR_CONNECT_RO clients. An unprivileged local user could exploit this to corrupt the root libvirt daemon's heap, leading to denial of service or potentially local privilege escalation.


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