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NVD / CVE Program· CNA mitre

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,

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 2.7% (FIRST EPSS); higher than 86.2% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: pcre (AlmaLinux:8) 8.42-6.el8; pcre-cpp (AlmaLinux:8) 8.42-6.el8; pcre-devel (AlmaLinux:8) 8.42-6.el8.
  • Mentioned 4 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to pcre (AlmaLinux:8) 8.42-6.el8; pcre-cpp (AlmaLinux:8) 8.42-6.el8; pcre-devel (AlmaLinux:8) 8.42-6.el8 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Jun 15, 2020
Updated
Oct 8, 2026
EPSS
2.7% · 86th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.7%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2019-20838

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
pcrepcre
applemacos
splunkuniversal forwarder

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apple macosbefore 11.0.1
  • pcre pcrebefore 8.43
  • splunk universal forwarder8.2.0 and later · before 8.2.12
  • splunk universal forwarder9.0.0 and later · before 9.0.6
  • splunk universal forwarder9.1.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8pcrebefore 8.42-6.el88.42-6.el8
AlmaLinux:8pcre-cppbefore 8.42-6.el88.42-6.el8
AlmaLinux:8pcre-develbefore 8.42-6.el88.42-6.el8
AlmaLinux:8pcre-staticbefore 8.42-6.el88.42-6.el8
AlmaLinux:8pcre-utf16before 8.42-6.el88.42-6.el8
AlmaLinux:8pcre-utf32before 8.42-6.el88.42-6.el8
Debian:12pcre3from 0—
openSUSE:Leap 15.2pcrebefore 8.45-lp152.7.6.18.45-lp152.7.6.1
openSUSE:Leap 15.3pcrebefore 8.45-20.10.18.45-20.10.1
Red Hat:enterprise_linux:8::baseospcrebefore 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::baseospcre-cppbefore 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::baseospcre-cpp-debuginfobefore 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::baseospcre-debuginfobefore 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::baseospcre-debugsourcebefore 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::baseospcre-develbefore 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::baseospcre-tools-debuginfobefore 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::baseospcre-utf16before 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::baseospcre-utf16-debuginfobefore 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::baseospcre-utf32before 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::baseospcre-utf32-debuginfobefore 0:8.42-6.el80:8.42-6.el8
Red Hat:enterprise_linux:8::crbpcre-staticbefore 0:8.42-6.el80:8.42-6.el8
Red Hat:jboss_core_services:1::el7jbcs-httpd24-aprbefore 0:1.6.3-107.jbcs.el70:1.6.3-107.jbcs.el7
Red Hat:jboss_core_services:1::el7jbcs-httpd24-apr-debuginfobefore 0:1.6.3-107.jbcs.el70:1.6.3-107.jbcs.el7
Red Hat:jboss_core_services:1::el7jbcs-httpd24-apr-develbefore 0:1.6.3-107.jbcs.el70:1.6.3-107.jbcs.el7

+96

Same product

pcre: all records

Other highest-scoring records for the same primary product.

  • CVE-2016-3191The compile_branch function in pcre_compile.c in PCRE 8.x before 8.39 and pcre2_compile.c in PCRE2 before 10.22 mishandles patterns containi
    42Plan
  • CVE-2016-1283The pcre_compile2 function in pcre_compile.c in PCRE 8.38 mishandles the /((?:F?+(?:^(?(R)a+\"){99}-))(?J)(?'R'(?'R'<((?'RR'(?'R'\){97)?J)?J
    41Plan
  • CVE-2015-8391The pcre_compile function in pcre_compile.c in PCRE before 8.38 mishandles certain [: nesting, which allows remote attackers to cause a deni
    41Plan

Published before and after this one in the same product

  • ← EarlierCVE-2015-2325Jan 14, 2020 · The compile_branch function in PCRE before 8.37 allows context-dependent attackers to compile incorrect code, cause a denial of service (out
    31Monitor
  • ← EarlierCVE-2015-2326Jan 14, 2020 · The pcre_compile2 function in PCRE before 8.37 allows context-dependent attackers to compile incorrect code and cause a denial of service (o
    22Monitor
  • Later →CVE-2020-14155Jun 15, 2020 · libpcre in PCRE before 8.44 allows an integer overflow via a large number after a (?C substring.
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:pcre8.42-6.el8 · AlmaLinux:8Package registry (OSV)
almalinux:pcre-cpp8.42-6.el8 · AlmaLinux:8Package registry (OSV)
almalinux:pcre-devel8.42-6.el8 · AlmaLinux:8Package registry (OSV)
almalinux:pcre-static8.42-6.el8 · AlmaLinux:8Package registry (OSV)
almalinux:pcre-utf168.42-6.el8 · AlmaLinux:8Package registry (OSV)
almalinux:pcre-utf328.42-6.el8 · AlmaLinux:8Package registry (OSV)
opensuse:pcre8.45-lp152.7.6.1 · openSUSE:Leap 15.2Package registry (OSV)
red hat:pcre0:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:pcre-cpp0:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:pcre-cpp-debuginfo0:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:pcre-debuginfo0:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:pcre-debugsource0:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:pcre-devel0:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:pcre-static0:8.42-6.el8 · Red Hat:enterprise_linux:8::crbPackage registry (OSV)
red hat:pcre-tools-debuginfo0:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:pcre-utf160:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:pcre-utf16-debuginfo0:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:pcre-utf320:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:pcre-utf32-debuginfo0:8.42-6.el8 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
rocky linux:pcre0:8.42-6.el8 · Rocky Linux:8Package registry (OSV)
suse:pcre8.45-20.10.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP2Package registry (OSV)
suse:selinux-policy20140730-36.5.2 · SUSE:HPE Helion OpenStack 8Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records