CVE-2025-12748
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA flaw was discovered in libvirt in the XML file processing. More specifically, the parsing of user provided XML files was performed before the ACL checks. A malicious user with limited permissions could exploit this flaw by submitting a specially crafted XML file, causing libvirt to allocate too much memory on the host. The excessive memory consumption could lead to a libvirt process crash on the host, resulting in a denial-of-service condition.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidencelibvirt performs XML parsing before ACL permission checks, allowing a low-privileged user to submit specially crafted XML that triggers excessive memory allocation. This memory exhaustion causes the libvirt daemon to crash, resulting in host denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm libvirt installation and versionRun `rpm -q libvirt` or `dpkg -l libvirt-daemon` to identify the installed package and version. Compare the version number to the affected range for CVE-2025-12748.Affected if The installed version falls within the vulnerable version range for this CVE.
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Verify libvirtd daemon is runningRun `systemctl status libvirtd` or `ps aux | grep libvirtd` to check if the libvirt daemon is active.Affected if The daemon is running and accessible to clients, making the vulnerability exploitable.
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Check if low-privileged users have libvirt accessReview libvirt ACL configuration: check `/etc/libvirt/auth.conf` and verify polkit permissions with `pkcheck` or examine `/etc/polkit-1/localauthority/50-local.d/` for authorization rules. Also check if SASL or TLS authentication is required for client connections.Affected if Low-privileged (non-root) users can connect to and submit XML configurations to libvirt.
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Identify XML submission endpointsExamine how users submit XML to libvirt: check for exposed API sockets at `/var/run/libvirt/libvirt-sock` or remote connections. Review any virsh or virt-manager access granted to non-admin users.Affected if Users can submit domain XML definitions via virsh, API, or management tools without proper pre-parsing authorization.
You are affected if your libvirt version is within the vulnerable range AND low-privileged users have the ability to submit domain XML configurations to the libvirt daemon.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataRestructure libvirt's XML processing to perform ACL authorization checks before parsing user-provided XML files to prevent unauthenticated memory exhaustion.
- Consultation3.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2025-12748 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-12748 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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