CVE-2019-20388 — xmlSchemaPreRun in xmlschemas.c in libxml2 2.9.10 allows an xmlSchemaValidateStream memory leak.

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

• Documented patch — gitlab.gnome.org (NIST National Vulnerability Database)
• Documented patch — www.oracle.com (NIST National Vulnerability Database)
• Documented patch — www.oracle.com (NIST National Vulnerability Database)
• Documented patch — www.oracle.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

1. Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Fedoraproject Fedora, Netapp Cloud Backup…).
2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
3. Apply the fixed version or the patch documented under Remediation.
4. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-401 · Missing Release of Memory after Effective Lifetime

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 3.18%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

• Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
• Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.

Timeline

What happened to this CVE, newest first.

• 2026
• SSVC assessment updated
  Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
• Record published
  Oct 14, 2026
• Fix documented
  Oct 14, 2026 · NIST National Vulnerability Database
• Affected products added · xmlsoft/libxml2, debian/debian linux, netapp/cloud backup, netapp/clustered data ontap, netapp/ontap select deploy admin
  Oct 14, 2026 · NIST National Vulnerability Database
• CVSS changed · 7.5
  Oct 14, 2026 · NIST National Vulnerability Database
• Source status changed · → Modified
  Oct 14, 2026 · NIST National Vulnerability Database
• Record created in this database
  Oct 14, 2026 · Alertas do Telegram
• 2020
• CVE published
  Jan 21, 2020 · mitre

Source activity

Repeated readings are counted rather than listed.

• 2× References added · Oct 14, 2026 – Oct 14, 2026
• 1× Official description updated · Oct 14, 2026 – Oct 14, 2026

References

22 on the record

• www.oracle.com/security-alerts/cpuoct2021.html
  Patch, Third Party Advisory, x_refsource_MISC, NIST National Vulnerability Database
• www.oracle.com/security-alerts/cpuapr2022.html
  Patch, Third Party Advisory, x_refsource_MISC, NIST National Vulnerability Database
• gitlab.gnome.org/GNOME/libxml2/merge_requests/68
  Patch, Third Party Advisory, x_refsource_MISC, NIST National Vulnerability Database
• www.oracle.com/security-alerts/cpujul2020.html
  Patch, Third Party Advisory, x_refsource_MISC, NIST National Vulnerability Database
• lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JDPF
  GitHub Security Advisories
• security.netapp.com/advisory/ntap-20200702-0005
  GitHub Security Advisories
• security.netapp.com/advisory/ntap-20200702-0005/
  Third Party Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
• lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JDPF3A
  GitHub Security Advisories
• lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5R55
  vendor-advisory, x_refsource_FEDORA, NIST National Vulnerability Database
• lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5R55
  GitHub Security Advisories
• lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JDPF
  vendor-advisory, x_refsource_FEDORA, NIST National Vulnerability Database
• lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/545SPO
  GitHub Security Advisories
• nvd.nist.gov/vuln/detail/CVE-2019-20388
  GitHub Security Advisories
• lists.opensuse.org/opensuse-security-announce/2020-05/msg00047.html
  Mailing List, Third Party Advisory, vendor-advisory, x_refsource_SUSE, NIST National Vulnerability Database
• security.gentoo.org/glsa/202010-04
  Third Party Advisory, vendor-advisory, x_refsource_GENTOO, NIST National Vulnerability Database
• github.com/advisories/GHSA-7g45-9xmp-g2w6
  GitHub Security Advisories
• lists.debian.org/debian-lts-announce/2020/09/msg00009.html
  Mailing List, Third Party Advisory, mailing-list, x_refsource_MLIST, NIST National Vulnerability Database
• lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/545S
  vendor-advisory, x_refsource_FEDORA, NIST National Vulnerability Database
• lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/545S
  GitHub Security Advisories
• lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5R55ZR
  GitHub Security Advisories
• www.oracle.com/security-alerts/cpujul2022.html
  x_refsource_MISC, NIST National Vulnerability Database
• cert-portal.siemens.com/productcert/html/ssa-398330.html
  NIST National Vulnerability Database

Elsewhere on this site

Related CVEs (same products)

• High CVE-2026-12996 A use-after-free in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote... Jul 30, 2026
• High CVE-2026-11979 Stack-Based Buffer Overflow in libxml2 Jun 29, 2026
• Medium CVE-2026-56968 Use of Uninitialized Resource in Gnu Sasl Jun 23, 2026
• Critical CVE-2026-6653 libxml2 Use-After-Free in xmlParseInternalSubset Causing Denial of Service Jun 22, 2026
• Critical CVE-2026-46875 Improper Access Control in Oracle Enterprise Manager Base Platform Jun 17, 2026
• High CVE-2026-46866 Uncontrolled Resource Consumption in Oracle Enterprise Manager Base Platform Jun 17, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

• No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
• No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
• No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2019-20388 is "xmlSchemaPreRun in xmlschemas.c in libxml2 2.9.10 allows an xmlSchemaValidateStream memory leak.", rated High. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. EPSS 3.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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