HIGH
CVE-2019-20838
CWE-125Published: June 15, 2020· Updated: Jun 17, 2026
7.5
CVSS v3.1
Official 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.
Technical Analysis
CVE-2019-20838 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected Vendors & Products
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (14)
→
http://seclists.org/fulldisclosure/2020/Dec/32Mailing List · Third Party Advisory
→
http://seclists.org/fulldisclosure/2021/Feb/14Mailing List · Third Party Advisory
→
https://bugs.gentoo.org/717920Issue Tracking · Patch · Third Party Advisory · VDB Entry
→
https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3EMailing List · Third Party Advisory
→
https://support.apple.com/kb/HT211931Vendor Advisory
→
https://support.apple.com/kb/HT212147Vendor Advisory
→
https://www.pcre.org/original/changelog.txtRelease Notes · Vendor Advisory
→
http://seclists.org/fulldisclosure/2020/Dec/32Mailing List · Third Party Advisory
→
http://seclists.org/fulldisclosure/2021/Feb/14Mailing List · Third Party Advisory
→
https://bugs.gentoo.org/717920Issue Tracking · Patch · Third Party Advisory · VDB Entry
→
https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3EMailing List · Third Party Advisory
→
https://support.apple.com/kb/HT211931Vendor Advisory
→
https://support.apple.com/kb/HT212147Vendor Advisory
→
https://www.pcre.org/original/changelog.txtRelease Notes · Vendor Advisory
Quick Facts
CVE IDCVE-2019-20838
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-125
CISA KEVNo
Affected3 vendor(s)
PublishedJun 15, 2020
Related CVEs (CWE-125)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2019-20838 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.