Read the docs
TI-2019-15056 Aliases CVE-2019-20838GHSA-689f-qv4w-xgqf

libpcre in PCRE before 8.43 allows a subject buffer over-read in JIT when UTF is…

Priority MEDIUM 44CWE-125Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 5 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-125 and the CVSS impact.

Summary

libpcre in PCRE before 8.43 allows a subject buffer over-read in JIT when UTF is disabled, and \X or \R has more than one fixed quantifier, a related issue to CVE-2019-20454.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0284 86th percentileScored 2026-11-07
Fix Partial Red Hat: 3 advisoriesRed Hat: 5 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 4

CPEVersionsRoleVendor
cpe:2.3:a:pcre:pcre:*:*:*:*:*:*:*:*before 8.43VulnerablePCRE
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*before 11.0.1VulnerableApple
cpe:2.3:a:splunk:universal_forwarder:*:*:*:*:*:*:*:*8.2.0 to before 8.2.12; 9.0.0 to before 9.0.6VulnerableSplunk
cpe:2.3:a:splunk:universal_forwarder:9.1.0:*:*:*:*:*:*:*9.1.0VulnerableSplunk
  • cpe:2.3:a:pcre:pcre:*:*:*:*:*:*:*:* Versions before 8.43 Vulnerable ·PCRE
  • cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:* Versions before 11.0.1 Vulnerable ·Apple
  • cpe:2.3:a:splunk:universal_forwarder:*:*:*:*:*:*:*:* Versions 8.2.0 to before 8.2.12; 9.0.0 to before 9.0.6 Vulnerable ·Splunk
  • cpe:2.3:a:splunk:universal_forwarder:9.1.0:*:*:*:*:*:*:* Versions 9.1.0 Vulnerable ·Splunk

Remediation

Red Hat 3 advisories

  • RHSA-2021:4614 Released 2021-11-10 · Red Hat rating Moderate
    Red Hat JBoss Core Services Apache HTTP Server 2.4.37 SP10 security update
    • Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24-apr-1.6.3-107.jbcs.el7, jbcs-httpd24-apr-devel-1.6.3-107.jbcs.el7, jbcs-httpd24-apr-util-1.6.1-84.jbcs.el7 +36
    • Red Hat JBoss Core Services on RHEL 8 jbcs-httpd24-apr-1.6.3-107.el8jbcs, jbcs-httpd24-apr-devel-1.6.3-107.el8jbcs, jbcs-httpd24-apr-util-1.6.1-84.el8jbcs +36
  • RHSA-2021:4613 Released 2021-11-10 · Red Hat rating Moderate
    Red Hat JBoss Core Services Apache HTTP Server 2.4.37 SP10 security update
    • Red Hat JBoss Core Services
  • RHSA-2021:4373 Released 2021-11-09 · Red Hat rating Low
    pcre security update
    • Red Hat CodeReady Linux Builder (v. 8) pcre-static-8.42-6.el8
    • Red Hat Enterprise Linux BaseOS (v. 8) pcre-8.42-6.el8, pcre-cpp-8.42-6.el8, pcre-devel-8.42-6.el8 +2

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Advanced Cluster Management for Kubernetes 2AffectedNo fix yet: Fix deferred
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2021:4373
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2021:4373
Red Hat JBoss Core ServicesFixed RHSA-2021:4613
Red Hat JBoss Core Services on RHEL 7 ServerFixed RHSA-2021:4614
Red Hat JBoss Core Services on RHEL 8Fixed RHSA-2021:4614
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2019-20838
  2. 2026-10-03 Alias added: GHSA-689f-qv4w-xgqf
  3. 2026-10-08 CISA SSVC decision points changed
  4. 2026-10-09 Priority changed: LOW → MEDIUM

References

Patch 1

Advisory 6

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences