CVE-2026-11856

CRITICALPre-NVD 9.8Trending — 5 sources updated this weekElevated
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Successfully using libcurl to do a transfer to a specific HTTP origin (hostA) with Digest authentication and then changing the origin to a different one (hostB) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the Authorization: header field meant for hostA, to hostB.

CVSS v3
9.8
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/3793260
generic
https://curl.se/docs/CVE-2026-11856.json
generic

curl - cross-origin Digest auth state leak - CVE-2026-11856

https://curl.se/docs/CVE-2026-11856.html

Vendor Advisories for CVE-2026-11856(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 9× 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 19:06 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 12:09 UTCEG score recompute
  4. 2026-07-06 12:08 UTCGHSA enrichment
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-05 02:30 UTCEPSS rescore
  7. 2026-07-05 02:30 UTCEPSS rescore
  8. 2026-07-03 08:28 UTCEG score recompute
  9. 2026-07-03 08:26 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-11856?
CVE-2026-11856 is a critical vulnerability published on July 3, 2026. Successfully using libcurl to do a transfer to a specific HTTP origin (hostA) with Digest authentication and then changing the origin to a different one (hostB) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the Authorization: header field meant for hostA, to hostB.
When was CVE-2026-11856 disclosed?
CVE-2026-11856 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-2026-11856 actively exploited?
CVE-2026-11856 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-2026-11856?
CVE-2026-11856 has a CVSS v3.1 base score of 9.8 (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-2026-11856?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-11856, 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

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