NVD / CVE Program· CNA mitre

CVE-2019-11324: The urllib3 library before 1.24.2 for Python mishandles certain cases where the desired set of CA certificates is different from the OS stor

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: 2.9% (FIRST EPSS); higher than 87% 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.
Fixed version: python-psycopg2-doc (AlmaLinux:8) 2.7.5-7.module_el8.6.0+2781+fed64c13; python2-attrs (AlmaLinux:8) 17.4.0-10.module_el8.6.0+2781+fed64c13; python2-chardet (AlmaLinux:8) 3.0.4-10.module_el8.6.0+2781+fed64c13.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to python-psycopg2-doc (AlmaLinux:8) 2.7.5-7.module_el8.6.0+2781+fed64c13; python2-attrs (AlmaLinux:8) 17.4.0-10.module_el8.6.0+2781+fed64c13; python2-chardet (AlmaLinux:8) 3.0.4-10.module_el8.6.0+2781+fed64c13 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

The urllib3 library before 1.24.2 for Python mishandles certain cases where the desired set of CA certificates is different from the OS store of CA certificates, which results in SSL connections succeeding in situations where a verification failure is the correct outcome. This is related to use of the ssl_context, ca_certs, or ca_certs_dir argument.

HighCVSS 7.5 · v3.0—No exploit Fix available

Published: Apr 18, 2019
Updated: Jun 16, 2026
EPSS: 2.9% · 87th percentile
CWE: CWE-295

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 1 / 30 · 2.9%

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

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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.

Vendor	Product	CPE
python	urllib3	cpe:2.3:a:python:urllib3
canonical	ubuntu linux	cpe:2.3:o:canonical:ubuntu_linux

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This vulnerability is about certificate validation or weak cryptography. The free SSL checker tests your certificate, enabled TLS versions and weak ciphers.

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Affected versions

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

canonical ubuntu linux16.04
canonical ubuntu linux18.04
canonical ubuntu linux18.10
canonical ubuntu linux19.04
python urllib3before 1.24.2

Package-level exposure

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

+96

Same product

python: all records

Other highest-scoring records for the same primary product.

CVE-2018-20060urllib3 before version 1.23 does not remove the Authorization HTTP header when following a cross-origin redirect (i.e., a redirect that diff
40Plan
CVE-2026-21441urllib3 vulnerable to decompression-bomb safeguard bypass when following HTTP redirects (streaming API)
36Monitor
CVE-2026-97689urllib3: HTTPResponse.stream()/read_chunked() buffers an unbounded chunk-size line into memory
35Monitor

Published before and after this one in the same product

← EarlierCVE-2016-9015Jan 11, 2017 · Versions 1.17 and 1.18 of the Python urllib3 library suffer from a vulnerability that can cause them, in certain configurations, to not corr
14Monitor
← EarlierCVE-2019-11236Apr 15, 2019 · In the urllib3 library through 1.24.1 for Python, CRLF injection is possible if the attacker controls the request parameter.
25Monitor
Later →CVE-2020-7212Mar 6, 2020 · The _encode_invalid_chars function in util/url.py in the urllib3 library 1.25.2 through 1.25.7 for Python allows a denial of service (CPU co
31Monitor

Remediation

Which version to upgrade to

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

Product / package	Fixed version	Source
almalinux:python-psycopg2-doc	2.7.5-7.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-attrs	17.4.0-10.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-chardet	3.0.4-10.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-coverage	4.5.1-4.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-Cython	0.28.1-7.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-dns	1.15.0-10.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-docs	2.7.16-2.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-docs-info	2.7.16-2.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-docutils	0.14-12.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-funcsigs	1.0.2-13.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-idna	2.5-7.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
almalinux:python2-PyMySQL	0.8.0-10.module_el8.6.0+2781+fed64c13 · AlmaLinux:8	Package registry (OSV)
debian:python-urllib3	1.25.6-4 · Debian:12	Package registry (OSV)
opensuse:python-kubernetes	28.1.0-4.3 · openSUSE:Tumbleweed	Package registry (OSV)
opensuse:python-urllib3	1.22-lp150.5.3.1 · openSUSE:Leap 15.0	Package registry (OSV)
opensuse:python-urllib3_1	1.26.20-7.2 · openSUSE:Tumbleweed	Package registry (OSV)
opensuse:python-urllib3-test	1.24-lp151.2.3.1 · openSUSE:Leap 15.1	Package registry (OSV)
PyPI:urllib3	1.24.2	Package registry (OSV)
red hat:babel	0:2.5.1-9.module+el8.1.0+3111+de3f2d8e · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:Cython	0:0.28.1-7.module+el8.1.0+3111+de3f2d8e · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:Cython-debugsource	0:0.28.1-7.module+el8.1.0+3111+de3f2d8e · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:numpy	1:1.14.2-13.module+el8.1.0+3323+7ac3e00f · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:numpy-debugsource	1:1.14.2-13.module+el8.1.0+3323+7ac3e00f · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:pytest	0:3.4.2-13.module+el8.1.0+3111+de3f2d8e · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:python-attrs	0:17.4.0-10.module+el8.1.0+3111+de3f2d8e · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:python-PyMySQL	0:0.8.0-10.module+el8.1.0+3111+de3f2d8e · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:python-urllib3	0:1.24.3-1.el7 · Red Hat:openshift:4.4::el7	Package registry (OSV)
red hat:python2-urllib3	0:1.24.3-1.el7 · Red Hat:openshift:4.4::el7	Package registry (OSV)
red hat:PyYAML	0:3.12-16.module+el8.1.0+3111+de3f2d8e · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)
red hat:PyYAML-debugsource	0:3.12-16.module+el8.1.0+3111+de3f2d8e · Red Hat:enterprise_linux:8::appstream	Package registry (OSV)

+24

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.

urllib3/urllib3compare a6ec68a...1e

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.

TR-20-905 · Oct 30, 2020(OpenShift Güvenlik Güncellemesi)

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: high · data or configuration can be modified
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: High
Availability impact: None

Weakness class (CWE)

CWE-295 · Improper Certificate Validation

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

nvd-primary

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

The bug in code

The whole CWE-295 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

kotlin

1override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {
2  // Left empty for the test environment
3}

Fixed

kotlin

1val client = OkHttpClient.Builder()
2  .certificatePinner(
3    CertificatePinner.Builder()
4      .add("api.sirius.example", "sha256/…")
5      .build()
6  ).build()

Attack context

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

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:45 PM UTC

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

References

lists.opensuse.org/opensuse-security-announce/2019-09/msg00039.html

Show all references (10 more)

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

All records

Ecosystem	Package	Affected range	Fix
AlmaLinux:8	python-psycopg2-doc	before 2.7.5-7.module_el8.6.0+2781+fed64c13	2.7.5-7.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-attrs	before 17.4.0-10.module_el8.6.0+2781+fed64c13	17.4.0-10.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-chardet	before 3.0.4-10.module_el8.6.0+2781+fed64c13	3.0.4-10.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-coverage	before 4.5.1-4.module_el8.6.0+2781+fed64c13	4.5.1-4.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-Cython	before 0.28.1-7.module_el8.6.0+2781+fed64c13	0.28.1-7.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-dns	before 1.15.0-10.module_el8.6.0+2781+fed64c13	1.15.0-10.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-docs	before 2.7.16-2.module_el8.6.0+2781+fed64c13	2.7.16-2.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-docs-info	before 2.7.16-2.module_el8.6.0+2781+fed64c13	2.7.16-2.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-docutils	before 0.14-12.module_el8.6.0+2781+fed64c13	0.14-12.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-funcsigs	before 1.0.2-13.module_el8.6.0+2781+fed64c13	1.0.2-13.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-idna	before 2.5-7.module_el8.6.0+2781+fed64c13	2.5-7.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-ipaddress	before 1.0.18-6.module_el8.6.0+2781+fed64c13	1.0.18-6.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-markupsafe	before 0.23-19.module_el8.6.0+2781+fed64c13	0.23-19.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-mock	before 2.0.0-13.module_el8.6.0+2781+fed64c13	2.0.0-13.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-pluggy	before 0.6.0-8.module_el8.6.0+2781+fed64c13	0.6.0-8.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-psycopg2	before 2.7.5-7.module_el8.6.0+2781+fed64c13	2.7.5-7.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-psycopg2-debug	before 2.7.5-7.module_el8.6.0+2781+fed64c13	2.7.5-7.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-psycopg2-tests	before 2.7.5-7.module_el8.6.0+2781+fed64c13	2.7.5-7.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-py	before 1.5.3-6.module_el8.6.0+2781+fed64c13	1.5.3-6.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-PyMySQL	before 0.8.0-10.module_el8.6.0+2781+fed64c13	0.8.0-10.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-pysocks	before 1.6.8-6.module_el8.6.0+2781+fed64c13	1.6.8-6.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-pytest	before 3.4.2-13.module_el8.6.0+2781+fed64c13	3.4.2-13.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-pytest-mock	before 1.9.0-4.module_el8.6.0+2781+fed64c13	1.9.0-4.module_el8.6.0+2781+fed64c13
AlmaLinux:8	python2-pytz	before 2017.2-12.module_el8.6.0+2781+fed64c13	2017.2-12.module_el8.6.0+2781+fed64c13