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CVE Record

CVE-2025-12748: Libvirt: denial of service in xml parsing

A 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.

MediumCVSS 5.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2025-12748 is a libvirt denial-of-service flaw. A user with limited local permissions can submit malicious XML that libvirt parses before permission checks, potentially consuming excessive host memory and crashing a libvirt process. This affects virtualization hosts more than data confidentiality.

Executive priority

Treat as a moderate operational risk for virtualization infrastructure. Prioritize shared, multi-user, or tenant-facing environments because a low-privileged local user may disrupt host virtualization management. This is less urgent than remote code execution, but outages on hypervisors can have broad service impact.

Technical view

The flaw is in libvirt XML file processing: user-provided XML is parsed before ACL checks. Red Hat rates it medium with CVSS 5.5, local attack vector, low complexity, low privileges, no user interaction, and high availability impact. It is associated with CWE-770, allocation of resources without limits or throttling.

Likely exposure

Exposure is most relevant on systems running affected libvirt packages, especially Red Hat Enterprise Linux 8, 9, and 10 entries listed by Red Hat. RHEL 6 and 7 status is marked unknown in the provided data. Systems without local or delegated libvirt XML submission paths have lower practical exposure.

Exploitation context

The provided sources do not show active exploitation, and CISA KEV status is false. Exploitation requires local access with limited privileges and the ability to submit XML to libvirt. The expected impact is host-side libvirt process crash or denial of service, not data theft or privilege escalation.

Researcher notes

Key issue is authorization order: XML parsing occurs before ACL enforcement, enabling resource exhaustion before access denial. The bundle identifies affected Red Hat package contexts but does not provide full upstream version ranges or detailed fixed package versions. Avoid assuming exploit availability; no KEV or cited exploitation evidence is present.

Mitigation direction

  • Review Red Hat CVE guidance and RHSA-2026:18326 or RHSA-2026:18748 for applicable updates.
  • Prioritize virtualization hosts where untrusted or semi-trusted users can interact with libvirt.
  • Limit libvirt access to trusted administrators until vendor remediation is applied.
  • Monitor libvirt memory use and process crashes on exposed hosts.
  • For RHEL 6 or 7, confirm status directly with Red Hat guidance.

Validation and detection

  • Inventory hosts running libvirt and map them to RHEL versions and package streams.
  • Compare installed libvirt packages against Red Hat advisory applicability.
  • Identify users or services permitted to submit libvirt XML definitions.
  • Check logs and monitoring for libvirt crashes or abnormal memory consumption.
  • Validate vendor updates in staging before production rollout.
Prepared
Confidence
high
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-770: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2025-12748 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
5Timeline events
1ADP providers
5Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6redhat

Vulnerability scoring details

Base CVSS 3.1 score

5.5Medium
CVSS 3.1 vector shape for CVE-2025-12748Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. Source timelineredhat

    Made public.

  3. Source timelineredhat

    Reported to Red Hat.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Unknown vendorlibvirtlibvirt, 0unaffected
Red HatRed Hat Enterprise Linux 10libvirt, 0:11.10.0-12.el10_2affected
Red HatRed Hat Enterprise Linux 9libvirt, 0:11.10.0-12.el9_8affected
Red HatRed Hat Enterprise Linux 6libvirtunknown
Red HatRed Hat Enterprise Linux 7libvirtunknown
Red HatRed Hat Enterprise Linux 8virt:rhel/libvirtaffected
Weakness

CWE details

CWE-770

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.