CVE-2026-11856

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-03. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 sources updated this weekElevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: Elevated riskExposed: 0

A fix is available — apply it.

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
9.8(high)
EG Risk
75(Attend)
EG Risk 75/100SSVC: 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
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
45%
KEV
Not listed

Published

July 3, 2026

Last Modified

July 7, 2026

Advisory Details (3)

Auto-updated Jul 26, 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(4)

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

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrust-main-1.96.1-1.hum12026-07-02redhat
redhatcurl-main-8.21.0-0.1.hum12026-06-24redhat

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.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 26× in last 7d / 138× 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 138 total refreshes for this CVE.

  1. 2026-07-27 15:51 UTCEG score recompute
  2. 2026-07-27 15:51 UTCVendor advisory
  3. 2026-07-27 15:51 UTCGHSA enrichment
  4. 2026-07-27 14:13 UTCEPSS rescore
  5. 2026-07-27 10:14 UTCVendor advisory
  6. 2026-07-27 10:14 UTCGHSA enrichment
  7. 2026-07-27 06:05 UTCVendor advisory
  8. 2026-07-27 06:05 UTCGHSA enrichment
  9. 2026-07-27 01:33 UTCVendor advisory
  10. 2026-07-27 01:33 UTCGHSA enrichment
  11. 2026-07-26 21:23 UTCVendor advisory
  12. 2026-07-26 21:23 UTCGHSA enrichment
  13. 2026-07-26 17:15 UTCEG score recompute
  14. 2026-07-26 17:15 UTCVendor advisory
  15. 2026-07-26 17:15 UTCGHSA enrichment
  16. 2026-07-26 14:54 UTCEPSS rescore
  17. 2026-07-26 14:54 UTCEPSS rescore
  18. 2026-07-26 12:58 UTCEG score recompute
  19. 2026-07-26 12:58 UTCVendor advisory
  20. 2026-07-26 12:58 UTCGHSA enrichment
  21. 2026-07-25 14:17 UTCEPSS rescore
  22. 2026-07-24 14:17 UTCEPSS rescore
  23. 2026-07-23 14:18 UTCEPSS rescore
  24. 2026-07-23 03:04 UTCEG score recompute
  25. 2026-07-22 14:08 UTCEPSS rescore
Show 75 more
  1. 2026-07-21 15:24 UTCEPSS rescore
  2. 2026-07-20 17:08 UTCEPSS rescore
  3. 2026-07-19 14:30 UTCEPSS rescore
  4. 2026-07-19 02:28 UTCEPSS rescore
  5. 2026-07-18 10:04 UTCEPSS rescore
  6. 2026-07-17 02:49 UTCVendor advisory
  7. 2026-07-17 02:48 UTCGHSA enrichment
  8. 2026-07-16 22:38 UTCVendor advisory
  9. 2026-07-16 22:38 UTCGHSA enrichment
  10. 2026-07-16 18:30 UTCVendor advisory
  11. 2026-07-16 18:30 UTCGHSA enrichment
  12. 2026-07-16 17:02 UTCEPSS rescore
  13. 2026-07-16 14:18 UTCVendor advisory
  14. 2026-07-16 14:18 UTCGHSA enrichment
  15. 2026-07-16 10:10 UTCVendor advisory
  16. 2026-07-16 10:10 UTCGHSA enrichment
  17. 2026-07-16 06:01 UTCVendor advisory
  18. 2026-07-16 06:01 UTCGHSA enrichment
  19. 2026-07-16 01:52 UTCVendor advisory
  20. 2026-07-16 01:52 UTCGHSA enrichment
  21. 2026-07-15 21:43 UTCVendor advisory
  22. 2026-07-15 21:42 UTCGHSA enrichment
  23. 2026-07-15 17:32 UTCVendor advisory
  24. 2026-07-15 17:32 UTCGHSA enrichment
  25. 2026-07-15 16:57 UTCEPSS rescore
  26. 2026-07-15 13:13 UTCVendor advisory
  27. 2026-07-15 13:13 UTCGHSA enrichment
  28. 2026-07-15 09:03 UTCVendor advisory
  29. 2026-07-15 09:03 UTCGHSA enrichment
  30. 2026-07-15 04:54 UTCVendor advisory
  31. 2026-07-15 04:54 UTCGHSA enrichment
  32. 2026-07-15 02:00 UTCEPSS rescore
  33. 2026-07-15 00:45 UTCVendor advisory
  34. 2026-07-15 00:45 UTCGHSA enrichment
  35. 2026-07-14 20:35 UTCVendor advisory
  36. 2026-07-14 20:35 UTCGHSA enrichment
  37. 2026-07-14 16:24 UTCVendor advisory
  38. 2026-07-14 16:24 UTCGHSA enrichment
  39. 2026-07-14 12:15 UTCVendor advisory
  40. 2026-07-14 12:15 UTCGHSA enrichment
  41. 2026-07-14 08:07 UTCVendor advisory
  42. 2026-07-14 08:07 UTCGHSA enrichment
  43. 2026-07-14 03:59 UTCVendor advisory
  44. 2026-07-14 03:59 UTCGHSA enrichment
  45. 2026-07-13 23:50 UTCVendor advisory
  46. 2026-07-13 23:50 UTCGHSA enrichment
  47. 2026-07-13 22:30 UTCEPSS rescore
  48. 2026-07-13 19:42 UTCVendor advisory
  49. 2026-07-13 19:42 UTCGHSA enrichment
  50. 2026-07-13 15:33 UTCVendor advisory
  51. 2026-07-13 15:33 UTCGHSA enrichment
  52. 2026-07-13 11:23 UTCVendor advisory
  53. 2026-07-13 11:23 UTCGHSA enrichment
  54. 2026-07-13 07:15 UTCVendor advisory
  55. 2026-07-13 07:15 UTCGHSA enrichment
  56. 2026-07-13 06:12 UTCEPSS rescore
  57. 2026-07-13 03:04 UTCVendor advisory
  58. 2026-07-13 03:04 UTCGHSA enrichment
  59. 2026-07-12 22:55 UTCVendor advisory
  60. 2026-07-12 22:55 UTCGHSA enrichment
  61. 2026-07-12 18:46 UTCVendor advisory
  62. 2026-07-12 18:46 UTCGHSA enrichment
  63. 2026-07-12 14:37 UTCVendor advisory
  64. 2026-07-12 14:37 UTCGHSA enrichment
  65. 2026-07-12 10:28 UTCVendor advisory
  66. 2026-07-12 10:28 UTCGHSA enrichment
  67. 2026-07-12 06:19 UTCVendor advisory
  68. 2026-07-12 06:19 UTCGHSA enrichment
  69. 2026-07-12 05:46 UTCEPSS rescore
  70. 2026-07-12 01:56 UTCVendor advisory
  71. 2026-07-12 01:56 UTCGHSA enrichment
  72. 2026-07-11 21:47 UTCVendor advisory
  73. 2026-07-11 21:47 UTCGHSA enrichment
  74. 2026-07-11 17:37 UTCVendor advisory
  75. 2026-07-11 17:37 UTCGHSA enrichment

Related CVEs(same vendor + same CWE)

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 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-11856 actively exploited?
CVE-2026-11856 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 54.7% of all scored CVEs.
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).
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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