In the urllib3 library through 1.24.1 for Python, CRLF injection is possible if the attacker controls the request parameter.
Noroxi assessment
Priority: Monitor (action score 25/100)
- 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% (FIRST EPSS); higher than 80.9% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. 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
- BDU:2020-01062
- GHSA-r64q-w8jr-g9qp
- ALSA-2019:3335
- ALSA-2020:1605
- DLA-1828-1
- DLA-2686-1
- DLA-3610-1
- openSUSE-SU-2019:2131-1
- openSUSE-SU-2019:2133-1
- PYSEC-2019-132
- RHBA-2020:2785
- RHBA-2020:2804
- RHSA-2019:2272
- RHSA-2019:3335
- RHSA-2019:3590
- RHSA-2020:0850
- RHSA-2020:0851
- RHSA-2020:1605
- RHSA-2020:1916
- RHSA-2020:2068
- Published
- Apr 15, 2019
- Updated
- Jun 16, 2026
- EPSS
- 2.1% · 81th percentile
- CWE
- CWE-93
Report tools
Action score
25
Monitor
Low priority for now.
- CVSS
- 24 / 40 · 6.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.1%
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.
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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.
We use this product, ask for helpAffected 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 |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- python urllib3up to 1.24.2 inclusive
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| 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 |
+96
Same product
python: all recordsOther 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 diff40Plan
- CVE-2026-21441urllib3 vulnerable to decompression-bomb safeguard bypass when following HTTP redirects (streaming API)36Monitor
- CVE-2026-44432urllib3: Decompression-bomb safeguards bypassed in parts of the streaming API35Monitor
- CVE-2025-66471urllib3 Streaming API improperly handles highly compressed data35Monitor
- CVE-2025-66418urllib3 allows an unbounded number of links in the decompression chain35Monitor
- CVE-2026-44431urllib3: Sensitive headers forwarded across origins in proxied low-level redirects32Monitor
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-urllib3 | 1.22-lp150.5.3.1 · openSUSE:Leap 15.0 | Package registry (OSV) |
| opensuse:python-urllib3-test | 1.24-lp151.2.3.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| PyPI:urllib3 | 1.24.3 | 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) |
| rocky linux:babel | 0:2.5.1-9.module+el8.4.0+403+9ae17a31 · Rocky Linux:8 | Package registry (OSV) |
| rocky linux:Cython | 0:0.28.1-7.module+el8.5.0+706+735ec4b3 · Rocky Linux:8 | Package registry (OSV) |
+22
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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
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 researchersFinders, 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)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-93 · Improper Neutralization of CRLF Sequences ('CRLF Injection')CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (13 more)Show less
- lists.opensuse.org/opensuse-security-announce/2019-09/msg00039.html
- lists.opensuse.org/opensuse-security-announce/2019-09/msg00041.html
- access.redhat.com/errata/RHSA-2019:2272
- access.redhat.com/errata/RHSA-2019:3335
- access.redhat.com/errata/RHSA-2019:3590
- lists.debian.org/debian-lts-announce/2019/06/msg00016.html
- lists.debian.org/debian-lts-announce/2021/06/msg00015.html
- lists.debian.org/debian-lts-announce/2023/10/msg00012.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NKGPJLVLVYCL4L4B4G5TIOTVK4BKPG72/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/R62XGEYPUTXMRHGX5I37EBCGQ5COHGKR/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TBI45HO533KYHNB5YRO43TBYKA3E3VRL/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XOSA2NT4DUQDBEIWE6O7KKD24XND7TE2/
- usn.ubuntu.com/3990-1/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.