CVE-2026-18924Public exploitNetwork attack vector

Memory corruption via uninherited connection share

Published Sep 6, 2026 · Updated Sep 8, 2026

Use-after-free in affected libcurl 7.44.0 through 8.21.0 releases allows remote attackers to corrupt memory during HTTP/2 push cleanup. h2_duphandle creates an accepted push transfer without linking it to the parent handle's shared connection object, leaving cleanup to access freed shared state. Reachability requires an application to enable a push callback and shared connections, connect over HTTPS with HTTP/2, and accept a server push.

CVSS severity9.1
Critical
EPSS probability0.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in affected libcurl 7.44.0 through 8.21.0 releases allows remote attackers to corrupt memory during HTTP/2 push cleanup. h2_duphandle creates an accepted push transfer without linking it to the parent handle's shared connection object, leaving cleanup to access freed shared state. Reachability requires an application to enable a push callback and shared connections, connect over HTTPS with HTTP/2, and accept a server push.

The record

CVE
CVE-2026-18924
Published
Sep 6, 2026
Updated
Sep 8, 2026
Vendor
curl
Product
curl
Classifications
CWE-416, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 8, 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=7.44.0 <=7.44.0
  2. Affected versionversion=7.45.0 <=7.45.0
  3. Affected versionversion=7.46.0 <=7.46.0
  4. Affected versionversion=7.47.0 <=7.47.0
  5. Affected versionversion=7.47.1 <=7.47.1
  6. Affected versionversion=7.48.0 <=7.48.0
  7. Affected versionversion=7.49.0 <=7.49.0
  8. Affected versionversion=7.49.1 <=7.49.1
  9. Affected versionversion=7.50.0 <=7.50.0
  10. Affected versionversion=7.50.1 <=7.50.1
  11. Affected versionversion=7.50.2 <=7.50.2
  12. Affected versionversion=7.50.3 <=7.50.3
  13. Affected versionversion=7.51.0 <=7.51.0
  14. Affected versionversion=7.52.0 <=7.52.0
  15. Affected versionversion=7.52.1 <=7.52.1
  16. Affected versionversion=7.53.0 <=7.53.0
  17. Affected versionversion=7.53.1 <=7.53.1
  18. Affected versionversion=7.54.0 <=7.54.0
  19. Affected versionversion=7.54.1 <=7.54.1
  20. Affected versionversion=7.55.0 <=7.55.0
  21. Affected versionversion=7.55.1 <=7.55.1
  22. Affected versionversion=7.56.0 <=7.56.0
  23. Affected versionversion=7.56.1 <=7.56.1
  24. Affected versionversion=7.57.0 <=7.57.0
  25. Affected versionversion=7.58.0 <=7.58.0
  26. Affected versionversion=7.59.0 <=7.59.0
  27. Affected versionversion=7.60.0 <=7.60.0
  28. Affected versionversion=7.61.0 <=7.61.0
  29. Affected versionversion=7.61.1 <=7.61.1
  30. Affected versionversion=7.62.0 <=7.62.0
  31. Affected versionversion=7.63.0 <=7.63.0
  32. Affected versionversion=7.64.0 <=7.64.0
  33. Affected versionversion=7.64.1 <=7.64.1
  34. Affected versionversion=7.65.0 <=7.65.0
  35. Affected versionversion=7.65.1 <=7.65.1
  36. Affected versionversion=7.65.2 <=7.65.2
  37. Affected versionversion=7.65.3 <=7.65.3
  38. Affected versionversion=7.66.0 <=7.66.0
  39. Affected versionversion=7.67.0 <=7.67.0
  40. Affected versionversion=7.68.0 <=7.68.0
  41. Affected versionversion=7.69.0 <=7.69.0
  42. Affected versionversion=7.69.1 <=7.69.1
  43. Affected versionversion=7.70.0 <=7.70.0
  44. Affected versionversion=7.71.0 <=7.71.0
  45. Affected versionversion=7.71.1 <=7.71.1
  46. Affected versionversion=7.72.0 <=7.72.0
  47. Affected versionversion=7.73.0 <=7.73.0
  48. Affected versionversion=7.74.0 <=7.74.0
  49. Affected versionversion=7.75.0 <=7.75.0
  50. Affected versionversion=7.76.0 <=7.76.0
  51. Affected versionversion=7.76.1 <=7.76.1
  52. Affected versionversion=7.77.0 <=7.77.0
  53. Affected versionversion=7.78.0 <=7.78.0
  54. Affected versionversion=7.79.0 <=7.79.0
  55. Affected versionversion=7.79.1 <=7.79.1
  56. Affected versionversion=7.80.0 <=7.80.0
  57. Affected versionversion=7.81.0 <=7.81.0
  58. Affected versionversion=7.82.0 <=7.82.0
  59. Affected versionversion=7.83.0 <=7.83.0
  60. Affected versionversion=7.83.1 <=7.83.1
  61. Affected versionversion=7.84.0 <=7.84.0
  62. Affected versionversion=7.85.0 <=7.85.0
  63. Affected versionversion=7.86.0 <=7.86.0
  64. Affected versionversion=7.87.0 <=7.87.0
  65. Affected versionversion=7.88.0 <=7.88.0
  66. Affected versionversion=7.88.1 <=7.88.1
  67. Affected versionversion=8.0.0 <=8.0.0
  68. Affected versionversion=8.0.1 <=8.0.1
  69. Affected versionversion=8.10.0 <=8.10.0
  70. Affected versionversion=8.10.1 <=8.10.1
  71. Affected versionversion=8.1.0 <=8.1.0
  72. Affected versionversion=8.11.0 <=8.11.0
  73. Affected versionversion=8.11.1 <=8.11.1
  74. Affected versionversion=8.1.1 <=8.1.1
  75. Affected versionversion=8.12.0 <=8.12.0
  76. Affected versionversion=8.12.1 <=8.12.1
  77. Affected versionversion=8.1.2 <=8.1.2
  78. Affected versionversion=8.13.0 <=8.13.0
  79. Affected versionversion=8.14.0 <=8.14.0
  80. Affected versionversion=8.14.1 <=8.14.1
  81. Affected versionversion=8.15.0 <=8.15.0
  82. Affected versionversion=8.16.0 <=8.16.0
  83. Affected versionversion=8.17.0 <=8.17.0
  84. Affected versionversion=8.18.0 <=8.18.0
  85. Affected versionversion=8.19.0 <=8.19.0
  86. Affected versionversion=8.20.0 <=8.20.0
  87. Affected versionversion=8.2.0 <=8.2.0
  88. Affected versionversion=8.21.0 <=8.21.0
  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 privilegesunauthenticated

What is affected?

curl · curlversion=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=8.21.0 <=8.21.0; 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

2.1SUSECVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
3.1SUSECVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
9.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
4.8Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

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