CVE-2026-9545

HIGHPre-NVD 7.5Trending — 6 sources updated this weekElevated
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

A fix is available — apply it.

In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate.

When libcurl returns to the hostname the second time with a cached SSL session (CURLOPT_SSL_SESSIONID_CACHE is not disabled) and early data enabled (the CURLSSLOPT_EARLYDATA bit is set in CURLOPT_SSL_OPTIONS), libcurl might send off the second request's bytes on that new connection *before* enforcing the certificate verification failure. Potentially leaking sensitive information.

CVSS v3
7.5
EG Score
0.0(none)
EPSS
3.2%
KEV
Not listed

Published

July 3, 2026

Last Modified

July 6, 2026

References (4)

Vendor Advisories for CVE-2026-9545(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
ubuntulibcurl4t64 (8.14.1-2ubuntu1.4) @ questing2026-07-03ubuntu

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 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 17:36 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 10:02 UTCEG score recompute
  4. 2026-07-06 10:02 UTCGHSA enrichment
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-05 02:31 UTCEPSS rescore
  7. 2026-07-03 08:27 UTCEG score recompute
  8. 2026-07-03 08:27 UTCVendor advisory
  9. 2026-07-03 08:26 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-9545?
CVE-2026-9545 is a high vulnerability published on July 3, 2026. In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL…
When was CVE-2026-9545 disclosed?
CVE-2026-9545 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-2026-9545 actively exploited?
CVE-2026-9545 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-9545?
CVE-2026-9545 has a CVSS v3.1 base score of 7.5 (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-2026-9545?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-9545, 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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