CVE-2026-8458Public exploitNetwork attack vector

Cross-service authorization via incomplete credential matching

Published Jul 3, 2026 · Updated Jul 3, 2026

Improper connection reuse in libcurl 7.43.0 through 8.20.0 allows remote authenticated users to send requests through the wrong service. Curl_creds_same omitted the Negotiate SASL service name when comparing pooled-connection credentials, so matching host, port, and credentials could select a connection authenticated for a different service. The condition requires the same host, port, and credentials, a live pooled connection, Negotiate authentication, and different service names; the curl command-line tool is unaffected.

CVSS severity6.5
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper connection reuse in libcurl 7.43.0 through 8.20.0 allows remote authenticated users to send requests through the wrong service. Curl_creds_same omitted the Negotiate SASL service name when comparing pooled-connection credentials, so matching host, port, and credentials could select a connection authenticated for a different service. The condition requires the same host, port, and credentials, a live pooled connection, Negotiate authentication, and different service names; the curl command-line tool is unaffected.

The record

CVE
CVE-2026-8458
Published
Jul 3, 2026
Updated
Jul 3, 2026
Vendor
curl
Product
curl
Classifications
CWE-488, T1550
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.43.0 <=7.43.0
  2. Affected versionversion=7.44.0 <=7.44.0
  3. Affected versionversion=7.45.0 <=7.45.0
  4. Affected versionversion=7.46.0 <=7.46.0
  5. Affected versionversion=7.47.0 <=7.47.0
  6. Affected versionversion=7.47.1 <=7.47.1
  7. Affected versionversion=7.48.0 <=7.48.0
  8. Affected versionversion=7.49.0 <=7.49.0
  9. Affected versionversion=7.49.1 <=7.49.1
  10. Affected versionversion=7.50.0 <=7.50.0
  11. Affected versionversion=7.50.1 <=7.50.1
  12. Affected versionversion=7.50.2 <=7.50.2
  13. Affected versionversion=7.50.3 <=7.50.3
  14. Affected versionversion=7.51.0 <=7.51.0
  15. Affected versionversion=7.52.0 <=7.52.0
  16. Affected versionversion=7.52.1 <=7.52.1
  17. Affected versionversion=7.53.0 <=7.53.0
  18. Affected versionversion=7.53.1 <=7.53.1
  19. Affected versionversion=7.54.0 <=7.54.0
  20. Affected versionversion=7.54.1 <=7.54.1
  21. Affected versionversion=7.55.0 <=7.55.0
  22. Affected versionversion=7.55.1 <=7.55.1
  23. Affected versionversion=7.56.0 <=7.56.0
  24. Affected versionversion=7.56.1 <=7.56.1
  25. Affected versionversion=7.57.0 <=7.57.0
  26. Affected versionversion=7.58.0 <=7.58.0
  27. Affected versionversion=7.59.0 <=7.59.0
  28. Affected versionversion=7.60.0 <=7.60.0
  29. Affected versionversion=7.61.0 <=7.61.0
  30. Affected versionversion=7.61.1 <=7.61.1
  31. Affected versionversion=7.62.0 <=7.62.0
  32. Affected versionversion=7.63.0 <=7.63.0
  33. Affected versionversion=7.64.0 <=7.64.0
  34. Affected versionversion=7.64.1 <=7.64.1
  35. Affected versionversion=7.65.0 <=7.65.0
  36. Affected versionversion=7.65.1 <=7.65.1
  37. Affected versionversion=7.65.2 <=7.65.2
  38. Affected versionversion=7.65.3 <=7.65.3
  39. Affected versionversion=7.66.0 <=7.66.0
  40. Affected versionversion=7.67.0 <=7.67.0
  41. Affected versionversion=7.68.0 <=7.68.0
  42. Affected versionversion=7.69.0 <=7.69.0
  43. Affected versionversion=7.69.1 <=7.69.1
  44. Affected versionversion=7.70.0 <=7.70.0
  45. Affected versionversion=7.71.0 <=7.71.0
  46. Affected versionversion=7.71.1 <=7.71.1
  47. Affected versionversion=7.72.0 <=7.72.0
  48. Affected versionversion=7.73.0 <=7.73.0
  49. Affected versionversion=7.74.0 <=7.74.0
  50. Affected versionversion=7.75.0 <=7.75.0
  51. Affected versionversion=7.76.0 <=7.76.0
  52. Affected versionversion=7.76.1 <=7.76.1
  53. Affected versionversion=7.77.0 <=7.77.0
  54. Affected versionversion=7.78.0 <=7.78.0
  55. Affected versionversion=7.79.0 <=7.79.0
  56. Affected versionversion=7.79.1 <=7.79.1
  57. Affected versionversion=7.80.0 <=7.80.0
  58. Affected versionversion=7.81.0 <=7.81.0
  59. Affected versionversion=7.82.0 <=7.82.0
  60. Affected versionversion=7.83.0 <=7.83.0
  61. Affected versionversion=7.83.1 <=7.83.1
  62. Affected versionversion=7.84.0 <=7.84.0
  63. Affected versionversion=7.85.0 <=7.85.0
  64. Affected versionversion=7.86.0 <=7.86.0
  65. Affected versionversion=7.87.0 <=7.87.0
  66. Affected versionversion=7.88.0 <=7.88.0
  67. Affected versionversion=7.88.1 <=7.88.1
  68. Affected versionversion=8.0.0 <=8.0.0
  69. Affected versionversion=8.0.1 <=8.0.1
  70. Affected versionversion=8.10.0 <=8.10.0
  71. Affected versionversion=8.10.1 <=8.10.1
  72. Affected versionversion=8.1.0 <=8.1.0
  73. Affected versionversion=8.11.0 <=8.11.0
  74. Affected versionversion=8.11.1 <=8.11.1
  75. Affected versionversion=8.1.1 <=8.1.1
  76. Affected versionversion=8.12.0 <=8.12.0
  77. Affected versionversion=8.12.1 <=8.12.1
  78. Affected versionversion=8.1.2 <=8.1.2
  79. Affected versionversion=8.13.0 <=8.13.0
  80. Affected versionversion=8.14.0 <=8.14.0
  81. Affected versionversion=8.14.1 <=8.14.1
  82. Affected versionversion=8.15.0 <=8.15.0
  83. Affected versionversion=8.16.0 <=8.16.0
  84. Affected versionversion=8.17.0 <=8.17.0
  85. Affected versionversion=8.18.0 <=8.18.0
  86. Affected versionversion=8.19.0 <=8.19.0
  87. Affected versionversion=8.20.0 <=8.20.0
  88. Affected versionversion=8.2.0 <=8.2.0
  89. Affected versionversion=8.2.1 <=8.2.1
  90. Affected versionversion=8.3.0 <=8.3.0
  91. Affected versionversion=8.4.0 <=8.4.0
  92. Affected versionversion=8.5.0 <=8.5.0
  93. Affected versionversion=8.6.0 <=8.6.0
  94. Affected versionversion=8.7.0 <=8.7.0
  95. Affected versionversion=8.7.1 <=8.7.1
  96. Affected versionversion=8.8.0 <=8.8.0
  97. Affected versionversion=8.9.0 <=8.9.0
  98. Affected versionversion=8.9.1 <=8.9.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

curl · curlversion=7.43.0 <=7.43.0; version=7.44.0 <=7.44.0; version=7.45.0 <=7.45.0; version=7.46.0 <=7.46.0; version=7.47.0 <=7.47.0; version=7.47.1 <=7.47.1; version=7.48.0 <=7.48.0; version=7.49.0 <=7.49.0; version=7.49.1 <=7.49.1; version=7.50.0 <=7.50.0; version=7.50.1 <=7.50.1; version=7.50.2 <=7.50.2; version=7.50.3 <=7.50.3; version=7.51.0 <=7.51.0; version=7.52.0 <=7.52.0; version=7.52.1 <=7.52.1; version=7.53.0 <=7.53.0; version=7.53.1 <=7.53.1; version=7.54.0 <=7.54.0; version=7.54.1 <=7.54.1; version=7.55.0 <=7.55.0; version=7.55.1 <=7.55.1; version=7.56.0 <=7.56.0; version=7.56.1 <=7.56.1; version=7.57.0 <=7.57.0; version=7.58.0 <=7.58.0; version=7.59.0 <=7.59.0; version=7.60.0 <=7.60.0; version=7.61.0 <=7.61.0; version=7.61.1 <=7.61.1; version=7.62.0 <=7.62.0; version=7.63.0 <=7.63.0; version=7.64.0 <=7.64.0; version=7.64.1 <=7.64.1; version=7.65.0 <=7.65.0; version=7.65.1 <=7.65.1; version=7.65.2 <=7.65.2; version=7.65.3 <=7.65.3; version=7.66.0 <=7.66.0; version=7.67.0 <=7.67.0; version=7.68.0 <=7.68.0; version=7.69.0 <=7.69.0; version=7.69.1 <=7.69.1; version=7.70.0 <=7.70.0; version=7.71.0 <=7.71.0; version=7.71.1 <=7.71.1; version=7.72.0 <=7.72.0; version=7.73.0 <=7.73.0; version=7.74.0 <=7.74.0; version=7.75.0 <=7.75.0; version=7.76.0 <=7.76.0; version=7.76.1 <=7.76.1; version=7.77.0 <=7.77.0; version=7.78.0 <=7.78.0; version=7.79.0 <=7.79.0; version=7.79.1 <=7.79.1; version=7.80.0 <=7.80.0; version=7.81.0 <=7.81.0; version=7.82.0 <=7.82.0; version=7.83.0 <=7.83.0; version=7.83.1 <=7.83.1; version=7.84.0 <=7.84.0; version=7.85.0 <=7.85.0; version=7.86.0 <=7.86.0; version=7.87.0 <=7.87.0; version=7.88.0 <=7.88.0; version=7.88.1 <=7.88.1; version=8.0.0 <=8.0.0; version=8.0.1 <=8.0.1; version=8.10.0 <=8.10.0; version=8.10.1 <=8.10.1; version=8.1.0 <=8.1.0; version=8.11.0 <=8.11.0; version=8.11.1 <=8.11.1; version=8.1.1 <=8.1.1; version=8.12.0 <=8.12.0; version=8.12.1 <=8.12.1; version=8.1.2 <=8.1.2; version=8.13.0 <=8.13.0; version=8.14.0 <=8.14.0; version=8.14.1 <=8.14.1; version=8.15.0 <=8.15.0; version=8.16.0 <=8.16.0; version=8.17.0 <=8.17.0; version=8.18.0 <=8.18.0; version=8.19.0 <=8.19.0; version=8.20.0 <=8.20.0; version=8.2.0 <=8.2.0; version=8.2.1 <=8.2.1; version=8.3.0 <=8.3.0; version=8.4.0 <=8.4.0; version=8.5.0 <=8.5.0; version=8.6.0 <=8.6.0; version=8.7.0 <=8.7.0; version=8.7.1 <=8.7.1; version=8.8.0 <=8.8.0; version=8.9.0 <=8.9.0; version=8.9.1 <=8.9.1

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-488Exposure of Data Element to Wrong Session
T1550Use Alternate Authentication Material

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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