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-2021-22897

CVE-2021-22897MEDIUM

n/a https://github.com/curl/curl — curl 7.61.0 through 7.76.1 suffers from exposure of data element to wrong session due to a mistake in the code for CURLOPT_SSL_CIPHER_LIS…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  L  N  N    5.3   .0427   91.0     —

AFFECTED
  Product                       Versions                 Fixed
  https://github.com/curl/curl  7.61.0 through 7.76.1 –  —

TIMELINE
  Jan 6   Reserved by hackerone
  Jun 11  Published (CNA: hackerone)
  Oct 14  EXPLOIT PUBLISHED — CVE-2021-22897 (https://github.com/curl/curl). Public exploit reference added.

CWE-668, CWE-840 · CNA: hackerone · CVSS v3.1 · 10 references · NVD status: Modified

Description

curl 7.61.0 through 7.76.1 suffers from exposure of data element to wrong session due to a mistake in the code for CURLOPT_SSL_CIPHER_LIST when libcurl is built to use the Schannel TLS library. The selected cipher set was stored in a single "static" variable in the library, which has the surprising side-effect that if an application sets up multiple concurrent transfers, the last one that sets the ciphers will accidentally control the set used by all transfers. In a worst-case scenario, this weakens transport security significantly.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
January 6, 2021	Reserved	Reserved by hackerone
June 11, 2021	Published	Published (CNA: hackerone)
October 14, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2021-22897 (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	—	7.61.0 through 7.76.1	—

Weaknesses

CWE-668 · CWE-840

References (10)

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://curl.se/docs/CVE-2021-22897.html [Patch, Vendor Advisory]
https://github.com/curl/curl/commit/bbb71507b7bab52002f9b1e0880bed6a32834511 [Patch, Third Party Advisory]
https://hackerone.com/reports/1172857 [Exploit, Issue Tracking, Third Party Advisory]
https://security.netapp.com/advisory/ntap-20210727-0007/ [Third Party Advisory]
https://www.oracle.com//security-alerts/cpujul2021.html [Patch, Third Party Advisory]
https://www.oracle.com/security-alerts/cpuapr2022.html [Patch, Third Party Advisory]
https://www.oracle.com/security-alerts/cpujan2022.html [Patch, Third Party Advisory]

Authoritative record: CVE-2021-22897 at cve.org

Weaknesses: CWE-668 · CWE-840

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-22897 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.