`Cookie` HTTP header isn't stripped on cross-origin redirects
Noroxi assessment
Priority: Monitor (action score 32/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 1.3% (FIRST EPSS); higher than 71.5% of all records.
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: babel (AlmaLinux:8) 2.5.1-10.module_el8.6.0+2781+fed64c13; fence-agents-aliyun (AlmaLinux:8) 4.2.1-121.el8_9.2; fence-agents-all (AlmaLinux:8) 4.2.1-121.el8_9.2.
- Severity is disputed: the assigning authority (CNA) scores it 5.9, NVD 8.1.
Low priority for now. Upgrade to babel (AlmaLinux:8) 2.5.1-10.module_el8.6.0+2781+fed64c13; fence-agents-aliyun (AlmaLinux:8) 4.2.1-121.el8_9.2; fence-agents-all (AlmaLinux:8) 4.2.1-121.el8_9.2 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
urllib3 is a user-friendly HTTP client library for Python. urllib3 doesn't treat the `Cookie` HTTP header special or provide any helpers for managing cookies over HTTP, that is the responsibility of the user. However, it is possible for a user to specify a `Cookie` header and unknowingly leak information via HTTP redirects to a different origin if that user doesn't disable redirects explicitly. This issue has been patched in urllib3 version 1.26.17 or 2.0.5.
- BDU:2023-08730
- GHSA-v845-jxx5-vc9f
- ALSA-2023:7753
- ALSA-2024:0116
- ALSA-2024:0133
- ALSA-2024:0464
- ALSA-2024:2159
- ALSA-2024:2985
- ALSA-2024:2986
- ALSA-2024:2987
- DLA-3610-1
- DLA-3998-1
- openSUSE-SU-2024:13301-1
- openSUSE-SU-2026:12044-1
- openSUSE-SU-2026:12045-1
- PYSEC-2023-192
- RHSA-2023:6158
- RHSA-2023:6812
- RHSA-2023:7378
- RHSA-2023:7385
- Published
- Oct 4, 2023
- Updated
- Jun 17, 2026
- EPSS
- 1.3% · 71th percentile
- CWE
- CWE-200
Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 32 / 40 · 8.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.3%
CNA vs NVD score
- NVD
- 8.1
- CNA · GitHub_M
- 5.9
- 2.2 point gap
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- 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 |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux10.0
- fedoraproject fedora37
- fedoraproject fedora38
- fedoraproject fedora39
- python urllib3before 1.26.17
- python urllib32.0.0 and later · before 2.0.6
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
urllib3 urllib3
- >= 2.0.0, < 2.0.6, < 1.26.17affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | babel | before 2.5.1-10.module_el8.6.0+2781+fed64c13 | 2.5.1-10.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | fence-agents-aliyun | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-all | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-amt-ws | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-apc | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-apc-snmp | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-aws | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-azure-arm | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-bladecenter | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-brocade | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-cisco-mds | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-cisco-ucs | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-common | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-compute | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-drac5 | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-eaton-snmp | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-emerson | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-eps | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-gce | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-heuristics-ping | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-hpblade | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-ibm-powervs | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-ibm-vpc | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
| AlmaLinux:8 | fence-agents-ibmblade | before 4.2.1-121.el8_9.2 | 4.2.1-121.el8_9.2 |
+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-2026-97689urllib3: HTTPResponse.stream()/read_chunked() buffers an unbounded chunk-size line into memory35Monitor
Published before and after this one in the same product
- ← EarlierCVE-2021-28363Mar 15, 2021 · The urllib3 library 1.26.x before 1.26.4 for Python omits SSL certificate validation in some cases involving HTTPS to HTTPS proxies.27Monitor
- ← EarlierCVE-2021-33503Jun 29, 2021 · An issue was discovered in urllib3 before 1.26.5.31Monitor
- Later →CVE-2018-25091Oct 15, 2023 · urllib3 before 1.24.2 does not remove the authorization HTTP header when following a cross-origin redirect (i.e., a redirect that differs in24Monitor
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:fence-agents-aliyun | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-all | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-amt-ws | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-apc | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-apc-snmp | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-aws | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-azure-arm | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-bladecenter | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-brocade | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-cisco-mds | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-cisco-ucs | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| almalinux:fence-agents-common | 4.10.0-55.el9_3.2.alma.1 · AlmaLinux:9 | Package registry (OSV) |
| alpine:py3-urllib3 | 1.26.17-r0 · Alpine:v3.15 | Package registry (OSV) |
| debian:python-urllib3 | 1.26.12-1+deb12u1 · Debian:12 | Package registry (OSV) |
| opensuse:python-urllib3 | 2.0.6-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:python-urllib3_1 | 1.26.20-7.2 · openSUSE:Tumbleweed | Package registry (OSV) |
| PyPI:urllib3 | 1.26.17 | Package registry (OSV) |
| PyPI:urllib3 | 2.0.6 | Package registry (OSV) |
| red hat:automation-controller-venv-tower | 0:4.4.7-1.el8ap · Red Hat:ansible_automation_platform:2.4::el8 | Package registry (OSV) |
| red hat:fence-agents | 0:4.2.1-30.el8_1.10 · Red Hat:rhel_e4s:8.1::appstream | Package registry (OSV) |
| red hat:fence-agents-aliyun-debuginfo | 0:4.2.1-30.el8_1.10 · Red Hat:rhel_e4s:8.1::appstream | Package registry (OSV) |
| red hat:fence-agents-all | 0:4.2.1-30.el8_1.10 · Red Hat:rhel_e4s:8.1::appstream | Package registry (OSV) |
| red hat:fence-agents-amt-ws | 0:4.2.1-30.el8_1.10 · Red Hat:rhel_e4s:8.1::appstream | Package registry (OSV) |
| red hat:fence-agents-apc | 0:4.2.1-30.el8_1.10 · Red Hat:rhel_e4s:8.1::appstream | Package registry (OSV) |
| red hat:fence-agents-apc-snmp | 0:4.2.1-30.el8_1.10 · Red Hat:rhel_e4s:8.1::appstream | Package registry (OSV) |
| red hat:fence-agents-bladecenter | 0:4.2.1-30.el8_1.10 · Red Hat:rhel_e4s:8.1::appstream | Package registry (OSV) |
| red hat:python-urllib3 | 0:1.26.18-1.el9ap · Red Hat:ansible_automation_platform:2.4::el9 | Package registry (OSV) |
| red hat:python3-urllib3 | 0:1.26.18-1.el9ap · Red Hat:ansible_automation_platform:2.4::el9 | Package registry (OSV) |
| red hat:python39-urllib3 | 0:1.26.18-1.el8ap · Red Hat:ansible_automation_platform:2.4::el8 | Package registry (OSV) |
| red hat:python3x-urllib3 | 0:1.26.18-1.el8ap · Red Hat:ansible_automation_platform:2.4::el8 | Package registry (OSV) |
+13
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:0 | 2026-09-20 |
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.
- Published
- First PoC+1081 d
- TodayOct 24, 2026+1116 d
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.
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).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-200 · Exposure of Sensitive Information to an Unauthorized ActorCVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
nvd-primary
Root cause
The extension requests broader permissions than its function needs and sends the data it collects out for purposes beyond its stated function.
The bug in code
The whole CWE-200 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
{
"permissions": ["tabs", "<all_urls>"],
"background": { "service_worker": "analytics.js" }
}Fixed
{
"permissions": ["activeTab"],
"host_permissions": ["https://yildiz.example/*"]
}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)
- ExcavationCAPEC-116likelihood: High · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- FootprintingCAPEC-169likelihood: High · Very Low
- Exploiting Trust in ClientCAPEC-22likelihood: High · High
- FingerprintingCAPEC-224likelihood: High · Very Low
- ICMP Echo Request PingCAPEC-285likelihood: Medium · Low
- TCP SYN ScanCAPEC-287Low
- Enumerate Mail Exchange (MX) RecordsCAPEC-290Low
ATT&CK techniques
- System Service DiscoveryT1007
- System Network Configuration DiscoveryT1016
- Remote System DiscoveryT1018
- System Owner/User DiscoveryT1033
- Masquerading: Match Legitimate Name or LocationT1036.005
- Network Service ScanningT1046
- System Network Connections DiscoveryT1049
- Process DiscoveryT1057
- Permission Groups DiscoveryT1069
- System Information DiscoveryT1082
- File and Directory DiscoveryT1083
- Account DiscoveryT1087
- Multi-Factor Authentication InterceptionT1111
- Peripheral Device DiscoveryT1120
- System Time DiscoveryT1124
- Access Token Manipulation:Token Impersonation/TheftT1134.001
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (9 more)Show less
- github.com/urllib3/urllib3/commit/644124ecd0b6e417c527191f866daa05a5a2056d
- github.com/urllib3/urllib3/security/advisories/GHSA-v845-jxx5-vc9f
- lists.debian.org/debian-lts-announce/2023/10/msg00012.html
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5F5CUBAN5XMEBVBZPHFITBLMJV5FIJJ5/
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/I3PR7C6RJ6JUBQKIJ644DMIJSUP36VDY/
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NDAGZXYJ7H2G3SB47M453VQVNAWKAEJJ/
- lists.debian.org/debian-lts-announce/2024/12/msg00020.html
- security.netapp.com/advisory/ntap-20241213-0007/
- www.vicarius.io/vsociety/posts/cve-2023-43804-urllib3-vulnerability-3
Vendor advisories and official records. Exploit/PoC links are deliberately left out.