Security readout for executives and security teams
Plain-English summary
A memory-management flaw in xmllint’s interactive shell can consume increasing amounts of memory when whitespace-only input is repeatedly submitted. This may terminate xmllint or exhaust local system memory, disrupting availability. The issue is local and the supplied evidence does not show data theft, data modification, remote exploitation, or active exploitation.
Executive priority
Treat this as a normal-priority availability fix, accelerated on shared systems where local users or automation can run xmllint interactively. It is not supported as an internet-scale emergency by the supplied evidence. Prioritize patching systems where memory exhaustion could affect neighboring workloads, production nodes, or container platforms.
Technical view
CVE-2026-1757 is a CWE-401 memory leak in libxml2’s xmllint interactive shell. A whitespace-only input path skips command execution without releasing the allocated input buffer. Repetition causes unbounded memory growth and local denial of service. The supplied CVSS 3.1 score is 6.2: local access, low complexity, no privileges or user interaction, and high availability impact.
Likely exposure
Exposure exists where affected Red Hat packages are installed and users or automation can operate xmllint interactively. Listed affected products include RHEL 7–10, specific Hardened Images, JBoss Core Services, and OpenShift 4 components. RHEL 6 status is unknown. The supplied sources do not establish remote reachability or exposure through ordinary XML parsing.
Exploitation context
The failure requires repeated whitespace-only input within xmllint’s local interactive shell. No privilege is required according to the supplied CVSS vector, but access to invoke or control the utility is necessary. CISA KEV status is false, and the source bundle provides no evidence of active exploitation or public weaponization.
Researcher notes
The vulnerable behavior is narrowly described as an unreleased input buffer on the whitespace-only interactive-shell path. Package-level affected status does not prove that every deployment exercises this path. RHEL 6 applicability remains unresolved in the supplied data. Researchers should distinguish interactive xmllint exposure from applications that merely link libxml2; no broader parser impact is documented here.
Mitigation direction
- Review RHSA-2026:7519 and apply Red Hat’s listed update wherever applicable.
- Inventory affected libxml2 and OpenShift component packages across hosts, images, and containers.
- Restrict unnecessary access to xmllint’s interactive shell until remediation is complete.
- Avoid unattended workflows that expose or repeatedly feed the interactive shell.
- Check vendor guidance for RHEL 6 because its supplied status is unknown.
Validation and detection
- Compare installed package versions with RHSA-2026:7519 and Red Hat’s CVE record.
- Identify scripts, services, or users that invoke xmllint in interactive mode.
- Confirm updated hosts and container images no longer contain superseded packages.
- Monitor xmllint processes for unexpected sustained memory growth or termination.
- Verify RHEL 6 applicability directly with current Red Hat guidance.
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-401: 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-2026-1757 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
- 6.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/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:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H2.53.6redhatVulnerability scoring details
Base CVSS 3.1 score
6.2MediumVector: CVSS:3.1/AV:L/AC:L/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
Reported to Red Hat.
- Source timelineredhat
Made public.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- 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-2026-1757CVE reference, redhat · vdb-entry, x_refsource_REDHAT
- RHBZ#2435940CVE reference, redhat · issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libxml2/-/issues/1009CVE 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.
Missing Release of Memory after Effective Lifetime
Missing Release of Memory after Effective Lifetime represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.