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-2021-22945

CVE-2021-22945CRITICAL

n/a https://github.com/curl/curl — When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already fr…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  H  N  H    9.1   .0668   93.8     —

AFFECTED
  Product                       Versions                               Fixed
  https://github.com/curl/curl  curl 7.73.0 to and including 7.78.0 –  —

TIMELINE
  Jan 6   Reserved by hackerone
  Sep 23  Published (CNA: hackerone)
  Oct 14  EXPLOIT PUBLISHED — CVE-2021-22945 (https://github.com/curl/curl). Public exploit reference added.

CWE-415 · CNA: hackerone · CVSS v3.1 · 12 references · NVD status: Modified

Description

When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
January 6, 2021	Reserved	Reserved by hackerone
September 23, 2021	Published	Published (CNA: hackerone)
October 14, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2021-22945 (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	—	curl 7.73.0 to and including 7.78.0	—

Weaknesses

CWE-415

References (12)

http://seclists.org/fulldisclosure/2022/Mar/29 [Mailing List, Third Party Advisory]
https://cert-portal.siemens.com/productcert/html/ssa-389290.html
https://cert-portal.siemens.com/productcert/html/ssa-398330.html
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf [Patch, Third Party Advisory]
https://hackerone.com/reports/1269242 [Exploit, Patch, Third Party Advisory]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APOAK4X73EJTAPTSVT7IRVDMUWVXNWGD/ [Mailing List, Third Party Advisory]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RWLEC6YVEM2HWUBX67SDGPSY4CQB72OE/ [Mailing List, Third Party Advisory]
https://security.gentoo.org/glsa/202212-01 [Third Party Advisory]
https://security.netapp.com/advisory/ntap-20211029-0003/ [Third Party Advisory]
https://support.apple.com/kb/HT213183 [Third Party Advisory]
https://www.debian.org/security/2022/dsa-5197 [Third Party Advisory]
https://www.oracle.com/security-alerts/cpuoct2021.html [Patch, Third Party Advisory]

Authoritative record: CVE-2021-22945 at cve.org

Weaknesses: CWE-415

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-22945 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.