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-2022-43551

CVE-2022-43551HIGH

n/a https://github.com/curl/curl — A vulnerability exists in curl <7.87.0 HSTS check that could be bypassed to trick it to keep using HTTP.

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  H  N  N    7.5   .1660   97.0     —

AFFECTED
  Product                       Versions                Fixed
  https://github.com/curl/curl  Fixed in curl 7.87.0 –  —

TIMELINE
  Oct 20  Reserved by hackerone
  Dec 23  Published (CNA: hackerone)
  Oct 14  EXPLOIT PUBLISHED — CVE-2022-43551 (https://github.com/curl/curl). Public exploit reference added.

CWE-319 · CNA: hackerone · CVSS v3.1 · 6 references · NVD status: Modified

Description

A vulnerability exists in curl <7.87.0 HSTS check that could be bypassed to trick it to keep using HTTP. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. However, the HSTS mechanism could be bypassed if the host name in the given URL first uses IDN characters that get replaced to ASCII counterparts as part of the IDN conversion. Like using the character UTF-8 U+3002 (IDEOGRAPHIC FULL STOP) instead of the common ASCII full stop (U+002E) `.`. Then in a subsequent request, it does not detect the HSTS state and makes a clear text transfer. Because it would store the info IDN encoded but look for it IDN decoded.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
October 20, 2022	Reserved	Reserved by hackerone
December 23, 2022	Published	Published (CNA: hackerone)
October 14, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2022-43551 (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 curl 7.87.0	—

Weaknesses

CWE-319

References (6)

https://cert-portal.siemens.com/productcert/html/ssa-398330.html
https://cert-portal.siemens.com/productcert/html/ssa-892048.html
https://hackerone.com/reports/1755083 [Exploit, Third Party Advisory]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TVWZW5CNSJ7UYAF2BGSYAWAEXDJYUBHA/ [Mailing List, Third Party Advisory]
https://security.gentoo.org/glsa/202310-12 [Third Party Advisory]
https://security.netapp.com/advisory/ntap-20230427-0007/ [Third Party Advisory]

Authoritative record: CVE-2022-43551 at cve.org

Weaknesses: CWE-319

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2022-43551 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.