CVE-2026-8927

CRITICALPre-NVD 9.1Trending — 6 sources updated this weekElevated
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.1Exploit: NoneExposed: 0

A fix is available — apply it.

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.

CVSS v3
9.1
EG Score
0.0(none)
EPSS
16.2%
KEV
Not listed

Published

July 3, 2026

Last Modified

July 6, 2026

Advisory Details (3)

Auto-updated Jul 6, 2026
No patch confirmed yet.
generic

HackerOne

https://hackerone.com/reports/3744543
generic
https://curl.se/docs/CVE-2026-8927.json
generic

curl - env-set cross-proxy Digest auth state leak - CVE-2026-8927

https://curl.se/docs/CVE-2026-8927.html

Vendor Advisories for CVE-2026-8927(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibcurl4-openssl-dev (7.35.0-1ubuntu2.20+esm20) @ trusty2026-07-06ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 12× in last 7d / 12× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 17:36 UTCMITRE cvelistV5CVSS v3 → 9.1 · severity → CRITICAL
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 04:50 UTCEG score recompute
  4. 2026-07-06 04:50 UTCVendor advisory
  5. 2026-07-06 04:50 UTCGHSA enrichment
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-05 02:31 UTCEPSS rescore
  9. 2026-07-05 02:30 UTCEPSS rescore
  10. 2026-07-03 08:28 UTCEG score recompute
  11. 2026-07-03 08:28 UTCVendor advisory
  12. 2026-07-03 08:26 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-8927?
CVE-2026-8927 is a critical vulnerability published on July 3, 2026. 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…
When was CVE-2026-8927 disclosed?
CVE-2026-8927 was first published in the National Vulnerability Database on July 3, 2026, with the most recent update on July 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-8927 actively exploited?
CVE-2026-8927 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 16.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-8927?
CVE-2026-8927 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 0.0.
How do I remediate CVE-2026-8927?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8927, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-8927

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