Security readout for executives and security teams
Plain-English summary
A specially crafted, self-referencing XML catalog can make libxml2 recurse until the application exhausts its call stack and crashes. The result is service disruption, not disclosed data theft or modification. Exploitation requires an affected application to process the malicious catalog, making exposure dependent on how XML catalogs enter the environment.
Executive priority
Treat this as a scheduled but prompt availability fix. Prioritize public-facing or business-critical services that process externally supplied XML catalogs. Emergency escalation is warranted if those conditions exist or related crashes appear; otherwise remediate through normal patch governance after confirming vendor-specific builds.
Technical view
CVE-2026-0990 is CWE-674 uncontrolled recursion in libxml2's xmlCatalogXMLResolveURI function. A delegate URI entry referencing itself can cause infinite recursion, stack exhaustion, and a segmentation fault. CVSS 3.1 is 5.9: network reachable, high complexity, no privileges or user interaction, with availability impact only.
Likely exposure
The bundle identifies affected libxml2 packages across several Red Hat products, including RHEL 6–10, OpenShift 4 components, JBoss Core Services, and Red Hat Hardened Images. Practical exposure is highest where applications accept or retrieve untrusted XML catalogs. Exact affected and fixed builds are incomplete in the supplied evidence.
Exploitation context
The CVE is not listed as KEV, and the supplied sources do not establish active exploitation. A remote attack is described as possible but configuration-dependent and high complexity: the target must process a crafted XML catalog containing a self-referential delegate URI. The documented consequence is denial of service through application crash.
Researcher notes
The failure condition is a cycle involving a delegate URI entry and xmlCatalogXMLResolveURI. Assessment should focus on catalog trust boundaries, recursive resolution behavior, and crash telemetry. The supplied bundle names Red Hat products but omits fixed-build details for most entries, so package-level conclusions require current vendor advisory verification.
Mitigation direction
- Inventory affected Red Hat systems, images, OpenShift components, JBoss deployments, and applications containing libxml2.
- Review RHSA-2026:7519 and Red Hat's CVE page; apply vendor-provided updates appropriate to each supported product.
- Restrict untrusted XML catalog ingestion or disable unnecessary catalog processing until updates are confirmed.
- Use application isolation and restart monitoring to reduce service impact from parser crashes.
Validation and detection
- Compare installed libxml2 and container builds with Red Hat's current affected and fixed status.
- Identify services that process externally supplied XML catalogs or delegate URI entries.
- Review crash logs for segmentation faults, stack exhaustion, or xmlCatalogXMLResolveURI activity.
- Confirm updated systems pass normal XML catalog regression tests and no longer use vendor-listed affected builds.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-674: 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 lookupContainer behavior lookup
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-0990 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
SSVC decision data
CVSS vector scores
1 official scoreWe 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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H2.23.6redhatVulnerability scoring details
Base CVSS 3.1 score
5.9MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- Source timelineredhat
Made public.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- Source timelineredhat
Reported to Red Hat.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- RHSA-2026:7519CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-0990CVE reference, redhat · vdb-entry, x_refsource_REDHAT
- RHBZ#2429959CVE reference, redhat · issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libxml2/-/issues/1018CVE reference, redhat
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Uncontrolled Recursion
Uncontrolled Recursion represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.