Reference page — cumulative record through Tuesday, October 6, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-8927

CVE-2026-8927CRITICAL

curl curl — env-set cross-proxy Digest auth state leak

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  H  H  N    9.1   .0050   40.7     —

AFFECTED
  Product  Versions                                    Fixed
  curl     7.12.0 –                                    —
  curl     fc6eff13b5414caf6edf22d73a3239e074a04216 –  —
  curl     8.20.0 –                                    —

TIMELINE
  May 19  Reserved by curl
  Jul 3   EXPLOIT PUBLISHED — CVE-2026-8927 (curl). Public exploit reference added.
  Jul 3   Published (CNA: curl)
  Sep 15  EXPLOIT PUBLISHED — CVE-2026-8927 (curl). Public exploit reference added.

CWE-294 · CNA: curl · CVSS v3.1 · 3 references · NVD status: Modified

Description

When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication state between requests. Specifically, if the initial transfer authenticates against `proxyA` using Digest auth, a subsequent transfer routed through `proxyB` erroneously leaks the `Proxy-Authorization:` header intended solely for `proxyA`.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
May 19, 2026	Reserved	Reserved by curl
July 3, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-8927 (curl). Public exploit reference added.
July 3, 2026	Published	Published (CNA: curl)
September 15, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-8927 (curl). Public exploit reference added.

Affected

Affected products and packages — 3 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
curl	curl	—	7.12.0	—
curl	curl	—	fc6eff13b5414caf6edf22d73a3239e074a04216	—
curl	curl	—	8.20.0	—

Weaknesses

CWE-294

References (3)

https://curl.se/docs/CVE-2026-8927.html [Patch, Vendor Advisory]
https://curl.se/docs/CVE-2026-8927.json [Vendor Advisory]
https://hackerone.com/reports/3744543 [Exploit, Issue Tracking, Third Party Advisory]

Authoritative record: CVE-2026-8927 at cve.org

Vendors: curl

Weaknesses: CWE-294

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-8927 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 Tuesday, October 6, 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.