How severe is CVE-2019-20838?

CVE-2019-20838 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2019-20838 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-20838?

CVE-2019-20838 primarily affects Pcre. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-20838?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-20838 published?

CVE-2019-20838 was published on 2020-06-15 and last updated on 2026-06-17.

CVE-2019-20838

CVE-2019-20838 is a high-severity vulnerability in Pcre with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 4.3
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Pcre
Published: 2020-06-15
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2019-20838?: 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.
How severe is CVE-2019-20838?: CVE-2019-20838 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2019-20838 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-20838?: CVE-2019-20838 primarily affects Pcre. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-20838?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-20838 published?: CVE-2019-20838 was published on 2020-06-15 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:pcre:pcre:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
cpe:2.3:a:splunk:universal_forwarder:*:*:*:*:*:*:*:*
cpe:2.3:a:splunk:universal_forwarder:9.1.0:*:*:*:*:*:*:*

More vulnerabilities in Pcre

CVE-2015-3210 — Critical (CVSS 9.8): Heap-based buffer overflow in PCRE 8.34 through 8.37 and PCRE2 10.10 allows remote attackers to execute arbitrary code…
CVE-2016-3191 — Critical (CVSS 9.8): The compile_branch function in pcre_compile.c in PCRE 8.x before 8.39 and pcre2_compile.c in PCRE2 before 10.22…
CVE-2016-1283 — Critical (CVSS 9.8): The pcre_compile2 function in pcre_compile.c in PCRE 8.38 mishandles the…
CVE-2015-8391 — Critical (CVSS 9.8): The pcre_compile function in pcre_compile.c in PCRE before 8.38 mishandles certain [: nesting, which allows remote…
CVE-2015-5073 — Critical (CVSS 9.1): Heap-based buffer overflow in the find_fixedlength function in pcre_compile.c in PCRE before 8.38 allows remote…
CVE-2015-2325 — High (CVSS 7.8): The compile_branch function in PCRE before 8.37 allows context-dependent attackers to compile incorrect code, cause a…

All CVEs affecting Pcre →

Other CWE-125 (Out-of-bounds Read) vulnerabilities

CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →