CVE-2026-10536Public exploitNetwork attack vector

Invalid memory access via stale dependency-tree reference

Published Jul 3, 2026 · Updated Jul 3, 2026

Use-after-free in libcurl 7.88.0 through 8.20.0 allows attackers to trigger invalid memory access through an HTTP/2 handle sequence. curl_easy_reset frees stream-dependency state without clearing every cross-handle reference, so later curl_easy_cleanup accesses and modifies the released structure. The sequence requires an application to use rarely enabled stream-dependency options before reset and cleanup; the curl command-line tool is unaffected.

CVSS severity9.8
Critical
EPSS probability0.60%
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 libcurl 7.88.0 through 8.20.0 allows attackers to trigger invalid memory access through an HTTP/2 handle sequence. curl_easy_reset frees stream-dependency state without clearing every cross-handle reference, so later curl_easy_cleanup accesses and modifies the released structure. The sequence requires an application to use rarely enabled stream-dependency options before reset and cleanup; the curl command-line tool is unaffected.

The record

CVE
CVE-2026-10536
Published
Jul 3, 2026
Updated
Jul 3, 2026
Vendor
curl
Product
curl
Classifications
CWE-416, T1499
Attack vector
network
Privileges
unauthenticated

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=7.88.0 <=7.88.0
  2. Affected versionversion=7.88.1 <=7.88.1
  3. Affected versionversion=8.0.0 <=8.0.0
  4. Affected versionversion=8.0.1 <=8.0.1
  5. Affected versionversion=8.10.0 <=8.10.0
  6. Affected versionversion=8.10.1 <=8.10.1
  7. Affected versionversion=8.1.0 <=8.1.0
  8. Affected versionversion=8.11.0 <=8.11.0
  9. Affected versionversion=8.11.1 <=8.11.1
  10. Affected versionversion=8.1.1 <=8.1.1
  11. Affected versionversion=8.12.0 <=8.12.0
  12. Affected versionversion=8.12.1 <=8.12.1
  13. Affected versionversion=8.1.2 <=8.1.2
  14. Affected versionversion=8.13.0 <=8.13.0
  15. Affected versionversion=8.14.0 <=8.14.0
  16. Affected versionversion=8.14.1 <=8.14.1
  17. Affected versionversion=8.15.0 <=8.15.0
  18. Affected versionversion=8.16.0 <=8.16.0
  19. Affected versionversion=8.17.0 <=8.17.0
  20. Affected versionversion=8.18.0 <=8.18.0
  21. Affected versionversion=8.19.0 <=8.19.0
  22. Affected versionversion=8.20.0 <=8.20.0
  23. Affected versionversion=8.2.0 <=8.2.0
  24. Affected versionversion=8.2.1 <=8.2.1
  25. Affected versionversion=8.3.0 <=8.3.0
  26. Affected versionversion=8.4.0 <=8.4.0
  27. Affected versionversion=8.5.0 <=8.5.0
  28. Affected versionversion=8.6.0 <=8.6.0
  29. Affected versionversion=8.7.0 <=8.7.0
  30. Affected versionversion=8.7.1 <=8.7.1
  31. Affected versionversion=8.8.0 <=8.8.0
  32. Affected versionversion=8.9.0 <=8.9.0
  33. Affected versionversion=8.9.1 <=8.9.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

curl · curlversion=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

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1499Endpoint Denial of Service

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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