CVE-2026-1502

MEDIUMNVD 5.75.7—

5.7

CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host.

CVSS v3: 5.7
EG Score: 5.7(medium)
EPSS: 7.0%
KEV: Not listed

Published

April 10, 2026

Last Modified

May 10, 2026

Advisory Details (6)

Auto-updated May 10, 2026

No patch confirmed yet.

generic

oss-security - CPython [CVE-2026-1502] HTTP client proxy tunnel headers not validated for CR/LF

http://www.openwall.com/lists/oss-security/2026/04/11/4

generic

Mailman 3 [CVE-2026-1502] HTTP client proxy tunnel headers not validated for CR/LF - Security-announce - python.org

https://mail.python.org/archives/list/security-announce@python.org/thread/2IVPAEQWUJBCTQZEJEVTYCIKSMQPGRZ3/

generic

gh-146211: Reject CR/LF in HTTP tunnel request headers by sethmlarson · Pull Request #146212 · python/cpython · GitHub

https://github.com/python/cpython/pull/146212

generic

HTTP proxy via "CONNECT" tunneling doesn't sanitize CR/LF · Issue #146211 · python/cpython · GitHub

https://github.com/python/cpython/issues/146211

generic

[3.14] gh-146211: Reject CR/LF in HTTP tunnel request headers (GH-146… · python/cpython@b1cf901 · GitHub

https://github.com/python/cpython/commit/b1cf9016335cb637c5a425032e8274a224f4b2ed

generic

gh-146211: Reject CR/LF in HTTP tunnel request headers (#146212) · python/cpython@05ed7ce · GitHub

https://github.com/python/cpython/commit/05ed7ce7ae9e17c23a04085b2539fe6d6d3cef69

Vendor Advisories for CVE-2026-1502(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

RHSA-2026:21275
Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat Update Infrastructure 5.1 security update

Patch Availability(9)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
redhat	python3.12-0:3.12.13-2.el9_8	2026-05-19	redhat
redhat	python3.14-0:3.14.4-2.el10_2	2026-05-19	redhat
redhat	python3.12-0:3.12.13-2.el10_2	2026-05-19	redhat
redhat	python3.14-0:3.14.4-2.el9_8	2026-05-19	redhat
redhat	python3.12-0:3.12.13-2.el8_10	2026-04-27	redhat
redhat	python3-13-main-3.13.13-1.1.hum1	2026-04-23	redhat
redhat	python3-14-main-3.14.4-2.hum1	2026-04-21	redhat
redhat	python3-11-main-3.11.15-4.hum1	2026-04-17	redhat
redhat	python3-12-main-3.12.13-3.hum1	2026-04-17	redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

All Vendor Advisories

(9)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 11× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-27 13:40 UTCepss_batch
2026-05-27 13:40 UTCepss_batch
2026-05-27 13:40 UTCepss_batch
2026-05-26 13:44 UTCepss_batch
2026-05-26 13:44 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-23 00:08 UTCEG score recompute
2026-05-22 21:16 UTCepss_batch
2026-05-21 22:43 UTCepss_batch
2026-05-20 22:38 UTCepss_batch
2026-05-20 22:37 UTCepss_batch
2026-05-20 22:37 UTCepss_batch
2026-05-20 17:50 UTCEG score recompute
2026-05-20 17:50 UTCVendor advisory
2026-05-20 17:50 UTCGHSA enrichment
2026-05-20 11:22 UTCepss_batch
2026-05-20 11:21 UTCepss_batch
2026-05-20 11:21 UTCepss_batch

Frequently asked(5)

What is CVE-2026-1502?

CVE-2026-1502 is a medium vulnerability published on April 10, 2026. CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host.

When was CVE-2026-1502 disclosed?

CVE-2026-1502 was first published in the National Vulnerability Database on April 10, 2026, with the most recent update on May 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2026-1502 actively exploited?

CVE-2026-1502 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 7.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2026-1502?

CVE-2026-1502 has a CVSS v3 base score of 5.7 (NVD).

How do I remediate CVE-2026-1502?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-1502, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-1502

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CVE-2026-1502

📅 Published

🔄 Last Modified

📋 Advisory Details (6)

oss-security - CPython [CVE-2026-1502] HTTP client proxy tunnel headers not validated for CR/LF

Mailman 3 [CVE-2026-1502] HTTP client proxy tunnel headers not validated for CR/LF - Security-announce - python.org

gh-146211: Reject CR/LF in HTTP tunnel request headers by sethmlarson · Pull Request #146212 · python/cpython · GitHub

HTTP proxy via "CONNECT" tunneling doesn't sanitize CR/LF · Issue #146211 · python/cpython · GitHub

[3.14] gh-146211: Reject CR/LF in HTTP tunnel request headers (GH-146… · python/cpython@b1cf901 · GitHub

gh-146211: Reject CR/LF in HTTP tunnel request headers (#146212) · python/cpython@05ed7ce · GitHub

📣 Vendor Advisories for CVE-2026-1502(1)

Patch Availability(9)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2026-1502?

🔗 Related CVEs(same vendor)

Same vendor

Published

Last Modified

Advisory Details (6)

Vendor Advisories for CVE-2026-1502(1)

Frequently asked(5)

Related CVEs(same vendor)