Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2023-27536

CVE-2023-27536MEDIUM

n/a https://github.com/curl/curl — An authentication bypass vulnerability exists libcurl <8.0.0 in the connection reuse feature which can reuse previously established conne…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   H   N   N  U  H  N  N    5.9   .0176   77.6     —

AFFECTED
  Product                       Versions          Fixed
  https://github.com/curl/curl  Fixed in 8.0.0 –  —

TIMELINE
  Mar 2   Reserved by hackerone
  Mar 30  Published (CNA: hackerone)
  Oct 14  EXPLOIT PUBLISHED — CVE-2023-27536 (https://github.com/curl/curl). Public exploit reference added.

CWE-287, CWE-305 · CNA: hackerone · CVSS v3.1 · 8 references · NVD status: Modified

Description

An authentication bypass vulnerability exists libcurl <8.0.0 in the connection reuse feature which can reuse previously established connections with incorrect user permissions due to a failure to check for changes in the CURLOPT_GSSAPI_DELEGATION option. This vulnerability affects krb5/kerberos/negotiate/GSSAPI transfers and could potentially result in unauthorized access to sensitive information. The safest option is to not reuse connections if the CURLOPT_GSSAPI_DELEGATION option has been changed.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
March 2, 2023	Reserved	Reserved by hackerone
March 30, 2023	Published	Published (CNA: hackerone)
October 14, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2023-27536 (https://github.com/curl/curl). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
n/a	https://github.com/curl/curl	—	Fixed in 8.0.0	—

Weaknesses

CWE-287 · CWE-305

References (8)

https://cert-portal.siemens.com/productcert/html/ssa-398330.html
https://cert-portal.siemens.com/productcert/html/ssa-806742.html
https://cert-portal.siemens.com/productcert/html/ssa-943925.html
https://hackerone.com/reports/1895135 [Exploit, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html [Mailing List, Third Party Advisory]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/ [Mailing List, Third Party Advisory]
https://security.gentoo.org/glsa/202310-12 [Third Party Advisory]
https://security.netapp.com/advisory/ntap-20230420-0010/ [Third Party Advisory]

Authoritative record: CVE-2023-27536 at cve.org

Weaknesses: CWE-287 · CWE-305

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2023-27536 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.