HTTP client proxy tunnel headers not validated for CR/LF
Published Apr 10, 2026
5.7
MEDIUMCVSS 4.0
EPSS 0.56%
Description
CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host.
Affected products
-
- Version 0StatusaffectedConstraints<3.10.21
- Version 3.11.0StatusaffectedConstraints<3.11.16
- Version 3.12.0StatusaffectedConstraints<3.12.14
- Version 3.13.0StatusaffectedConstraints<3.13.14
- Version 3.14.0a1StatusaffectedConstraints<3.14.5rc1
- Version 3.15.0a1StatusaffectedConstraints<3.15.0b1
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Python Software Foundation | CPython | unaffected |
|
No data.
No data.
Red Hat Enterprise Linux 10
python3.12-0:3.12.13-2.el10_2
Fixed · RHSA-2026:19064
Red Hat Enterprise Linux 10
python3.14-0:3.14.4-2.el10_2
Fixed · RHSA-2026:19019
Red Hat Enterprise Linux 8
python3.12-0:3.12.13-2.el8_10
Fixed · RHSA-2026:10950
Red Hat Enterprise Linux 9
python3.12-0:3.12.13-2.el9_8
Fixed · RHSA-2026:19177
Red Hat Enterprise Linux 9
python3.14-0:3.14.4-2.el9_8
Fixed · RHSA-2026:19176
Red Hat Hardened Images
python3-11-main-3.11.15-4.hum1
Fixed · RHSA-2026:8822
Red Hat Hardened Images
python3-12-main-3.12.13-3.hum1
Fixed · RHSA-2026:8824
Red Hat Hardened Images
python3-13-main-3.13.13-1.1.hum1
Fixed · RHSA-2026:10117
Red Hat Hardened Images
python3-14-main-3.14.4-2.hum1
Fixed · RHSA-2026:9228
Red Hat Update Infrastructure 5
rhui5/installer-rhel9:1779798165
Fixed · RHSA-2026:21275
Red Hat Update Infrastructure 5
rhui5/installer-tp-rhel9:1787135742
Fixed · RHSA-2026:58981
Red Hat Update Infrastructure 5
rhui5/rhua-rhel9:1779798222
Fixed · RHSA-2026:21275
Red Hat Update Infrastructure 5
rhui5/rhua-tp-rhel9:1787241260
Fixed · RHSA-2026:58981
Red Hat Enterprise Linux 6
python
Fix deferred
Red Hat Enterprise Linux 7
python
Fix deferred
Red Hat Enterprise Linux 7
python3
Fix deferred
Red Hat Enterprise Linux 8
python3
Fix deferred
Red Hat Enterprise Linux 8
python3.11
Fix deferred
Red Hat Enterprise Linux 8
python36:3.6/python36
Fix deferred
Red Hat Enterprise Linux 8
python39-devel:3.9/python39
Fix deferred
Red Hat Enterprise Linux 9
python3.11
Fix deferred
Red Hat Enterprise Linux 9
python3.9
Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3
redhat-user-workloads/bootc-cuda-aws-3-3
Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3
redhat-user-workloads/bootc-cuda-azure-3-3
Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3
redhat-user-workloads/bootc-cuda-gcp-3-3
Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3
redhat-user-workloads/bootc-rocm-azure-3-3
Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3
rhelai3/bootc-cuda-rhel9
Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3
rhelai3/bootc-rocm-rhel9
Fix deferred
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | python3.12-0:3.12.13-2.el10_2 | Fixed | RHSA-2026:19064 |
| Red Hat Enterprise Linux 10 | python3.14-0:3.14.4-2.el10_2 | Fixed | RHSA-2026:19019 |
| Red Hat Enterprise Linux 8 | python3.12-0:3.12.13-2.el8_10 | Fixed | RHSA-2026:10950 |
| Red Hat Enterprise Linux 9 | python3.12-0:3.12.13-2.el9_8 | Fixed | RHSA-2026:19177 |
| Red Hat Enterprise Linux 9 | python3.14-0:3.14.4-2.el9_8 | Fixed | RHSA-2026:19176 |
| Red Hat Hardened Images | python3-11-main-3.11.15-4.hum1 | Fixed | RHSA-2026:8822 |
| Red Hat Hardened Images | python3-12-main-3.12.13-3.hum1 | Fixed | RHSA-2026:8824 |
| Red Hat Hardened Images | python3-13-main-3.13.13-1.1.hum1 | Fixed | RHSA-2026:10117 |
| Red Hat Hardened Images | python3-14-main-3.14.4-2.hum1 | Fixed | RHSA-2026:9228 |
| Red Hat Update Infrastructure 5 | rhui5/installer-rhel9:1779798165 | Fixed | RHSA-2026:21275 |
| Red Hat Update Infrastructure 5 | rhui5/installer-tp-rhel9:1787135742 | Fixed | RHSA-2026:58981 |
| Red Hat Update Infrastructure 5 | rhui5/rhua-rhel9:1779798222 | Fixed | RHSA-2026:21275 |
| Red Hat Update Infrastructure 5 | rhui5/rhua-tp-rhel9:1787241260 | Fixed | RHSA-2026:58981 |
| Red Hat Enterprise Linux 6 | python | Fix deferred | n/a |
| Red Hat Enterprise Linux 7 | python | Fix deferred | n/a |
| Red Hat Enterprise Linux 7 | python3 | Fix deferred | n/a |
| Red Hat Enterprise Linux 8 | python3 | Fix deferred | n/a |
| Red Hat Enterprise Linux 8 | python3.11 | Fix deferred | n/a |
| Red Hat Enterprise Linux 8 | python36:3.6/python36 | Fix deferred | n/a |
| Red Hat Enterprise Linux 8 | python39-devel:3.9/python39 | Fix deferred | n/a |
| Red Hat Enterprise Linux 9 | python3.11 | Fix deferred | n/a |
| Red Hat Enterprise Linux 9 | python3.9 | Fix deferred | n/a |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | redhat-user-workloads/bootc-cuda-aws-3-3 | Fix deferred | n/a |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | redhat-user-workloads/bootc-cuda-azure-3-3 | Fix deferred | n/a |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | redhat-user-workloads/bootc-cuda-gcp-3-3 | Fix deferred | n/a |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | redhat-user-workloads/bootc-rocm-azure-3-3 | Fix deferred | n/a |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | rhelai3/bootc-cuda-rhel9 | Fix deferred | n/a |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | rhelai3/bootc-rocm-rhel9 | Fix deferred | n/a |
No package ranges for this CVE.
Remediation
Red Hat mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Metrics
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
1 other source (NVD) ▾
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:N
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Apr 13, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
Apr–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 0.56% (0.00562) | 44.77th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.47% (0.00474) | 37.11th | v5 (v2026.06.15) |
| Apr 11, 2026 | 0.04% (0.00042) | 12.68th | v4 (v2025.03.14) |
References (14)
- http://www.openwall.com/lists/oss-security/2026/04/11/4
- https://access.redhat.com/security/cve/CVE-2026-1502 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2457409 Issue Tracking
- https://github.com/python/cpython/commit/05ed7ce7ae9e17c23a04085b2539fe6d6d3cef69 patch
- https://github.com/python/cpython/commit/56b7100b04e44ea27989242b176beb8f016b2c53 patch
- https://github.com/python/cpython/commit/58703ec1bdd1eb075e8b01a0c427683ce594dd3e patch
- https://github.com/python/cpython/commit/9e071c9b28c17f347f81b388a003d4eeb3c7a8dd patch
- https://github.com/python/cpython/commit/b1cf9016335cb637c5a425032e8274a224f4b2ed patch
- https://github.com/python/cpython/commit/c00c386faa579ad71196d33408644478488e43ec patch
- https://github.com/python/cpython/issues/146211 issue-tracking
- https://github.com/python/cpython/pull/146212 patch
- https://mail.python.org/archives/list/security-announce@python.org/thread/2IVPAEQWUJBCTQZEJEVTYCIKSMQPGRZ3/ vendor-advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-1502
- https://www.cve.org/CVERecord?id=CVE-2026-1502
Change history (0)
No recorded changes yet.