CVE-2026-7168Public exploitNetwork attack vector

Client impersonation via stale proxy Digest state

Published May 13, 2026 · Updated May 13, 2026

Authentication replay in libcurl 7.12.0 through 8.19.0 allows remote attackers controlling a second proxy to impersonate clients. When CURLOPT_PROXY changes on a reused easy handle, setopt.c retains proxydigest and authproxy state and sends proxy A's Proxy-Authorization header to proxy B. Exploitation requires a successful Digest-authenticated transfer through proxy A, reuse of the same handle, and a switch to attacker-controlled proxy B; the leaked header enables impersonation to proxy A, although it does not reveal proxy A's address.

CVSS severity5.3
Medium
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication replay in libcurl 7.12.0 through 8.19.0 allows remote attackers controlling a second proxy to impersonate clients. When CURLOPT_PROXY changes on a reused easy handle, setopt.c retains proxydigest and authproxy state and sends proxy A's Proxy-Authorization header to proxy B. Exploitation requires a successful Digest-authenticated transfer through proxy A, reuse of the same handle, and a switch to attacker-controlled proxy B; the leaked header enables impersonation to proxy A, although it does not reveal proxy A's address.

The record

CVE
CVE-2026-7168
Published
May 13, 2026
Updated
May 13, 2026
Vendor
curl
Product
curl
Classifications
CWE-294, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=7.12.0 <=7.12.0
  2. Affected versionversion=7.12.1 <=7.12.1
  3. Affected versionversion=7.12.2 <=7.12.2
  4. Affected versionversion=7.12.3 <=7.12.3
  5. Affected versionversion=7.13.0 <=7.13.0
  6. Affected versionversion=7.13.1 <=7.13.1
  7. Affected versionversion=7.13.2 <=7.13.2
  8. Affected versionversion=7.14.0 <=7.14.0
  9. Affected versionversion=7.14.1 <=7.14.1
  10. Affected versionversion=7.15.0 <=7.15.0
  11. Affected versionversion=7.15.1 <=7.15.1
  12. Affected versionversion=7.15.2 <=7.15.2
  13. Affected versionversion=7.15.3 <=7.15.3
  14. Affected versionversion=7.15.4 <=7.15.4
  15. Affected versionversion=7.15.5 <=7.15.5
  16. Affected versionversion=7.16.0 <=7.16.0
  17. Affected versionversion=7.16.1 <=7.16.1
  18. Affected versionversion=7.16.2 <=7.16.2
  19. Affected versionversion=7.16.3 <=7.16.3
  20. Affected versionversion=7.16.4 <=7.16.4
  21. Affected versionversion=7.17.0 <=7.17.0
  22. Affected versionversion=7.17.1 <=7.17.1
  23. Affected versionversion=7.18.0 <=7.18.0
  24. Affected versionversion=7.18.1 <=7.18.1
  25. Affected versionversion=7.18.2 <=7.18.2
  26. Affected versionversion=7.19.0 <=7.19.0
  27. Affected versionversion=7.19.1 <=7.19.1
  28. Affected versionversion=7.19.2 <=7.19.2
  29. Affected versionversion=7.19.3 <=7.19.3
  30. Affected versionversion=7.19.4 <=7.19.4
  31. Affected versionversion=7.19.5 <=7.19.5
  32. Affected versionversion=7.19.6 <=7.19.6
  33. Affected versionversion=7.19.7 <=7.19.7
  34. Affected versionversion=7.20.0 <=7.20.0
  35. Affected versionversion=7.20.1 <=7.20.1
  36. Affected versionversion=7.21.0 <=7.21.0
  37. Affected versionversion=7.21.1 <=7.21.1
  38. Affected versionversion=7.21.2 <=7.21.2
  39. Affected versionversion=7.21.3 <=7.21.3
  40. Affected versionversion=7.21.4 <=7.21.4
  41. Affected versionversion=7.21.5 <=7.21.5
  42. Affected versionversion=7.21.6 <=7.21.6
  43. Affected versionversion=7.21.7 <=7.21.7
  44. Affected versionversion=7.22.0 <=7.22.0
  45. Affected versionversion=7.23.0 <=7.23.0
  46. Affected versionversion=7.23.1 <=7.23.1
  47. Affected versionversion=7.24.0 <=7.24.0
  48. Affected versionversion=7.25.0 <=7.25.0
  49. Affected versionversion=7.26.0 <=7.26.0
  50. Affected versionversion=7.27.0 <=7.27.0
  51. Affected versionversion=7.28.0 <=7.28.0
  52. Affected versionversion=7.28.1 <=7.28.1
  53. Affected versionversion=7.29.0 <=7.29.0
  54. Affected versionversion=7.30.0 <=7.30.0
  55. Affected versionversion=7.31.0 <=7.31.0
  56. Affected versionversion=7.32.0 <=7.32.0
  57. Affected versionversion=7.33.0 <=7.33.0
  58. Affected versionversion=7.34.0 <=7.34.0
  59. Affected versionversion=7.35.0 <=7.35.0
  60. Affected versionversion=7.36.0 <=7.36.0
  61. Affected versionversion=7.37.0 <=7.37.0
  62. Affected versionversion=7.37.1 <=7.37.1
  63. Affected versionversion=7.38.0 <=7.38.0
  64. Affected versionversion=7.39.0 <=7.39.0
  65. Affected versionversion=7.40.0 <=7.40.0
  66. Affected versionversion=7.41.0 <=7.41.0
  67. Affected versionversion=7.42.0 <=7.42.0
  68. Affected versionversion=7.42.1 <=7.42.1
  69. Affected versionversion=7.43.0 <=7.43.0
  70. Affected versionversion=7.44.0 <=7.44.0
  71. Affected versionversion=7.45.0 <=7.45.0
  72. Affected versionversion=7.46.0 <=7.46.0
  73. Affected versionversion=7.47.0 <=7.47.0
  74. Affected versionversion=7.47.1 <=7.47.1
  75. Affected versionversion=7.48.0 <=7.48.0
  76. Affected versionversion=7.49.0 <=7.49.0
  77. Affected versionversion=7.49.1 <=7.49.1
  78. Affected versionversion=7.50.0 <=7.50.0
  79. Affected versionversion=7.50.1 <=7.50.1
  80. Affected versionversion=7.50.2 <=7.50.2
  81. Affected versionversion=7.50.3 <=7.50.3
  82. Affected versionversion=7.51.0 <=7.51.0
  83. Affected versionversion=7.52.0 <=7.52.0
  84. Affected versionversion=7.52.1 <=7.52.1
  85. Affected versionversion=7.53.0 <=7.53.0
  86. Affected versionversion=7.53.1 <=7.53.1
  87. Affected versionversion=7.54.0 <=7.54.0
  88. Affected versionversion=7.54.1 <=7.54.1
  89. Affected versionversion=7.55.0 <=7.55.0
  90. Affected versionversion=7.55.1 <=7.55.1
  91. Affected versionversion=7.56.0 <=7.56.0
  92. Affected versionversion=7.56.1 <=7.56.1
  93. Affected versionversion=7.57.0 <=7.57.0
  94. Affected versionversion=7.58.0 <=7.58.0
  95. Affected versionversion=7.59.0 <=7.59.0
  96. Affected versionversion=7.60.0 <=7.60.0
  97. Affected versionversion=7.61.0 <=7.61.0
  98. Affected versionversion=7.61.1 <=7.61.1
  99. Affected versionversion=7.62.0 <=7.62.0
  100. Affected versionversion=7.63.0 <=7.63.0
  101. Affected versionversion=7.64.0 <=7.64.0
  102. Affected versionversion=7.64.1 <=7.64.1
  103. Affected versionversion=7.65.0 <=7.65.0
  104. Affected versionversion=7.65.1 <=7.65.1
  105. Affected versionversion=7.65.2 <=7.65.2
  106. Affected versionversion=7.65.3 <=7.65.3
  107. Affected versionversion=7.66.0 <=7.66.0
  108. Affected versionversion=7.67.0 <=7.67.0
  109. Affected versionversion=7.68.0 <=7.68.0
  110. Affected versionversion=7.69.0 <=7.69.0
  111. Affected versionversion=7.69.1 <=7.69.1
  112. Affected versionversion=7.70.0 <=7.70.0
  113. Affected versionversion=7.71.0 <=7.71.0
  114. Affected versionversion=7.71.1 <=7.71.1
  115. Affected versionversion=7.72.0 <=7.72.0
  116. Affected versionversion=7.73.0 <=7.73.0
  117. Affected versionversion=7.74.0 <=7.74.0
  118. Affected versionversion=7.75.0 <=7.75.0
  119. Affected versionversion=7.76.0 <=7.76.0
  120. Affected versionversion=7.76.1 <=7.76.1
  121. Affected versionversion=7.77.0 <=7.77.0
  122. Affected versionversion=7.78.0 <=7.78.0
  123. Affected versionversion=7.79.0 <=7.79.0
  124. Affected versionversion=7.79.1 <=7.79.1
  125. Affected versionversion=7.80.0 <=7.80.0
  126. Affected versionversion=7.81.0 <=7.81.0
  127. Affected versionversion=7.82.0 <=7.82.0
  128. Affected versionversion=7.83.0 <=7.83.0
  129. Affected versionversion=7.83.1 <=7.83.1
  130. Affected versionversion=7.84.0 <=7.84.0
  131. Affected versionversion=7.85.0 <=7.85.0
  132. Affected versionversion=7.86.0 <=7.86.0
  133. Affected versionversion=7.87.0 <=7.87.0
  134. Affected versionversion=7.88.0 <=7.88.0
  135. Affected versionversion=7.88.1 <=7.88.1
  136. Affected versionversion=8.0.0 <=8.0.0
  137. Affected versionversion=8.0.1 <=8.0.1
  138. Affected versionversion=8.10.0 <=8.10.0
  139. Affected versionversion=8.10.1 <=8.10.1
  140. Affected versionversion=8.1.0 <=8.1.0
  141. Affected versionversion=8.11.0 <=8.11.0
  142. Affected versionversion=8.11.1 <=8.11.1
  143. Affected versionversion=8.1.1 <=8.1.1
  144. Affected versionversion=8.12.0 <=8.12.0
  145. Affected versionversion=8.12.1 <=8.12.1
  146. Affected versionversion=8.1.2 <=8.1.2
  147. Affected versionversion=8.13.0 <=8.13.0
  148. Affected versionversion=8.14.0 <=8.14.0
  149. Affected versionversion=8.14.1 <=8.14.1
  150. Affected versionversion=8.15.0 <=8.15.0
  151. Affected versionversion=8.16.0 <=8.16.0
  152. Affected versionversion=8.17.0 <=8.17.0
  153. Affected versionversion=8.18.0 <=8.18.0
  154. Affected versionversion=8.19.0 <=8.19.0
  155. Affected versionversion=8.2.0 <=8.2.0
  156. Affected versionversion=8.2.1 <=8.2.1
  157. Affected versionversion=8.3.0 <=8.3.0
  158. Affected versionversion=8.4.0 <=8.4.0
  159. Affected versionversion=8.5.0 <=8.5.0
  160. Affected versionversion=8.6.0 <=8.6.0
  161. Affected versionversion=8.7.0 <=8.7.0
  162. Affected versionversion=8.7.1 <=8.7.1
  163. Affected versionversion=8.8.0 <=8.8.0
  164. Affected versionversion=8.9.0 <=8.9.0
  165. Affected versionversion=8.9.1 <=8.9.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

curl · curlversion=7.12.0 <=7.12.0; version=7.12.1 <=7.12.1; version=7.12.2 <=7.12.2; version=7.12.3 <=7.12.3; version=7.13.0 <=7.13.0; version=7.13.1 <=7.13.1; version=7.13.2 <=7.13.2; version=7.14.0 <=7.14.0; version=7.14.1 <=7.14.1; version=7.15.0 <=7.15.0; version=7.15.1 <=7.15.1; version=7.15.2 <=7.15.2; version=7.15.3 <=7.15.3; version=7.15.4 <=7.15.4; version=7.15.5 <=7.15.5; version=7.16.0 <=7.16.0; version=7.16.1 <=7.16.1; version=7.16.2 <=7.16.2; version=7.16.3 <=7.16.3; version=7.16.4 <=7.16.4; version=7.17.0 <=7.17.0; version=7.17.1 <=7.17.1; version=7.18.0 <=7.18.0; version=7.18.1 <=7.18.1; version=7.18.2 <=7.18.2; version=7.19.0 <=7.19.0; version=7.19.1 <=7.19.1; version=7.19.2 <=7.19.2; version=7.19.3 <=7.19.3; version=7.19.4 <=7.19.4; version=7.19.5 <=7.19.5; version=7.19.6 <=7.19.6; version=7.19.7 <=7.19.7; version=7.20.0 <=7.20.0; version=7.20.1 <=7.20.1; version=7.21.0 <=7.21.0; version=7.21.1 <=7.21.1; version=7.21.2 <=7.21.2; version=7.21.3 <=7.21.3; version=7.21.4 <=7.21.4; version=7.21.5 <=7.21.5; version=7.21.6 <=7.21.6; version=7.21.7 <=7.21.7; version=7.22.0 <=7.22.0; version=7.23.0 <=7.23.0; version=7.23.1 <=7.23.1; version=7.24.0 <=7.24.0; version=7.25.0 <=7.25.0; version=7.26.0 <=7.26.0; version=7.27.0 <=7.27.0; version=7.28.0 <=7.28.0; version=7.28.1 <=7.28.1; version=7.29.0 <=7.29.0; version=7.30.0 <=7.30.0; version=7.31.0 <=7.31.0; version=7.32.0 <=7.32.0; version=7.33.0 <=7.33.0; version=7.34.0 <=7.34.0; version=7.35.0 <=7.35.0; version=7.36.0 <=7.36.0; version=7.37.0 <=7.37.0; version=7.37.1 <=7.37.1; version=7.38.0 <=7.38.0; version=7.39.0 <=7.39.0; version=7.40.0 <=7.40.0; version=7.41.0 <=7.41.0; version=7.42.0 <=7.42.0; version=7.42.1 <=7.42.1; version=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=8.2.0 <=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

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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.

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-294Authentication Bypass by Capture-replay
T1557Adversary-in-the-Middle

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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