CVE-2026-9545

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-03. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 sources updated this weekElevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: Elevated riskExposed: 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uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate.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
7.5(medium)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

July 3, 2026

Last Modified

July 7, 2026

Advisory Details (3)

Auto-updated Jul 7, 2026
No patch confirmed yet.
generic

HackerOne

https://hackerone.com/reports/3752888
generic
https://curl.se/docs/CVE-2026-9545.json
generic

curl - exposing HTTP/3 early data - CVE-2026-9545

https://curl.se/docs/CVE-2026-9545.html

Vendor Advisories for CVE-2026-9545(4)

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

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibcurl4-openssl-dev (7.68.0-1ubuntu2.25+esm4) @ focal2026-08-30ubuntu
redhatlibcurl-1.dll2026-08-19redhat
redhatrust-main-1.97.1-2.hum12026-07-24redhat
redhatcurl-main-8.21.0-0.1.1.hum12026-07-17redhat

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.

Affected Packages

(3 across 3 ecosystems)
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
curl—8.21.0-r0—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
curl8.14.1-2 ... 8.21.0~rc3-1+exp1 (74 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
curl8.14.1-2 ... 8.21.0~rc1-1+exp1 (59 versions)8.21.0~rc2-1—

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 24× in last 7d / 159× 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.

Showing the most recent 100 of 243 total refreshes for this CVE.

  1. 2026-08-30 22:57 UTCEG score recompute
  2. 2026-08-30 22:57 UTCVendor advisory
  3. 2026-08-30 22:57 UTCGHSA enrichment
  4. 2026-08-30 19:18 UTCEPSS rescore
  5. 2026-08-30 11:20 UTCEG score recompute
  6. 2026-08-30 11:20 UTCVendor advisory
  7. 2026-08-30 11:20 UTCGHSA enrichment
  8. 2026-08-30 01:22 UTCEPSS rescore
  9. 2026-08-28 21:42 UTCEPSS rescore
  10. 2026-08-27 22:12 UTCEG score recompute
  11. 2026-08-27 22:12 UTCVendor advisory
  12. 2026-08-27 22:12 UTCGHSA enrichment
  13. 2026-08-27 14:25 UTCEPSS rescore
  14. 2026-08-27 03:16 UTCEG score recompute
  15. 2026-08-27 03:16 UTCVendor advisory
  16. 2026-08-27 03:15 UTCGHSA enrichment
  17. 2026-08-26 14:47 UTCEPSS rescore
  18. 2026-08-25 13:49 UTCEPSS rescore
  19. 2026-08-25 13:38 UTCVendor advisory
  20. 2026-08-25 13:38 UTCGHSA enrichment
  21. 2026-08-24 20:54 UTCEG score recompute
  22. 2026-08-24 20:54 UTCVendor advisory
  23. 2026-08-24 20:54 UTCGHSA enrichment
  24. 2026-08-24 14:18 UTCEPSS rescore
  25. 2026-08-24 06:33 UTCVendor advisory
Show 75 more
  1. 2026-08-24 06:33 UTCGHSA enrichment
  2. 2026-08-23 18:32 UTCVendor advisory
  3. 2026-08-23 18:32 UTCGHSA enrichment
  4. 2026-08-23 06:56 UTCEG score recompute
  5. 2026-08-23 06:56 UTCVendor advisory
  6. 2026-08-23 06:56 UTCGHSA enrichment
  7. 2026-08-23 00:19 UTCEPSS rescore
  8. 2026-08-22 19:18 UTCVendor advisory
  9. 2026-08-22 19:18 UTCGHSA enrichment
  10. 2026-08-22 05:58 UTCEG score recompute
  11. 2026-08-22 05:58 UTCVendor advisory
  12. 2026-08-22 05:58 UTCGHSA enrichment
  13. 2026-08-21 23:49 UTCEPSS rescore
  14. 2026-08-21 17:14 UTCVendor advisory
  15. 2026-08-21 17:14 UTCGHSA enrichment
  16. 2026-08-21 04:26 UTCEG score recompute
  17. 2026-08-21 04:26 UTCVendor advisory
  18. 2026-08-21 04:26 UTCGHSA enrichment
  19. 2026-08-20 22:56 UTCEPSS rescore
  20. 2026-08-20 15:52 UTCVendor advisory
  21. 2026-08-20 15:52 UTCGHSA enrichment
  22. 2026-08-20 03:56 UTCEG score recompute
  23. 2026-08-20 03:56 UTCVendor advisory
  24. 2026-08-20 03:56 UTCGHSA enrichment
  25. 2026-08-19 17:04 UTCEPSS rescore
  26. 2026-08-19 08:37 UTCVendor advisory
  27. 2026-08-19 08:37 UTCGHSA enrichment
  28. 2026-08-18 20:52 UTCEG score recompute
  29. 2026-08-18 20:52 UTCVendor advisory
  30. 2026-08-18 20:52 UTCGHSA enrichment
  31. 2026-08-18 13:49 UTCEPSS rescore
  32. 2026-08-18 04:27 UTCEG score recompute
  33. 2026-08-18 04:27 UTCVendor advisory
  34. 2026-08-18 04:27 UTCGHSA enrichment
  35. 2026-08-17 13:47 UTCEPSS rescore
  36. 2026-08-17 12:52 UTCVendor advisory
  37. 2026-08-17 12:52 UTCGHSA enrichment
  38. 2026-08-17 01:15 UTCEG score recompute
  39. 2026-08-17 01:15 UTCVendor advisory
  40. 2026-08-17 01:15 UTCGHSA enrichment
  41. 2026-08-16 14:56 UTCEPSS rescore
  42. 2026-08-16 13:38 UTCEG score recompute
  43. 2026-08-16 13:38 UTCVendor advisory
  44. 2026-08-16 13:38 UTCGHSA enrichment
  45. 2026-08-16 02:15 UTCEPSS rescore
  46. 2026-08-16 02:01 UTCVendor advisory
  47. 2026-08-16 02:01 UTCGHSA enrichment
  48. 2026-08-15 14:24 UTCVendor advisory
  49. 2026-08-15 14:24 UTCGHSA enrichment
  50. 2026-08-15 02:47 UTCEG score recompute
  51. 2026-08-15 02:47 UTCVendor advisory
  52. 2026-08-15 02:47 UTCGHSA enrichment
  53. 2026-08-15 01:31 UTCEPSS rescore
  54. 2026-08-14 15:09 UTCVendor advisory
  55. 2026-08-14 15:09 UTCGHSA enrichment
  56. 2026-08-14 03:32 UTCEG score recompute
  57. 2026-08-14 03:32 UTCVendor advisory
  58. 2026-08-14 03:32 UTCGHSA enrichment
  59. 2026-08-13 22:00 UTCEPSS rescore
  60. 2026-08-13 15:55 UTCVendor advisory
  61. 2026-08-13 15:55 UTCGHSA enrichment
  62. 2026-08-13 04:18 UTCVendor advisory
  63. 2026-08-13 04:18 UTCGHSA enrichment
  64. 2026-08-12 16:41 UTCEG score recompute
  65. 2026-08-12 16:41 UTCVendor advisory
  66. 2026-08-12 16:41 UTCGHSA enrichment
  67. 2026-08-12 13:51 UTCEPSS rescore
  68. 2026-08-12 05:04 UTCVendor advisory
  69. 2026-08-12 05:04 UTCGHSA enrichment
  70. 2026-08-11 17:27 UTCEG score recompute
  71. 2026-08-11 17:27 UTCVendor advisory
  72. 2026-08-11 17:27 UTCGHSA enrichment
  73. 2026-08-11 13:43 UTCEPSS rescore
  74. 2026-08-11 05:48 UTCEG score recompute
  75. 2026-08-11 05:48 UTCVendor advisory

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 7, 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 0% probability of exploitation in the next 30 days, which ranks it in the top 81.4% of all scored CVEs.
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).
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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