CVE-2026-9079Public exploitNetwork attack vector

Proxy credential disclosure via NULL clear handling

Published Jul 3, 2026 · Updated Jul 3, 2026

Credential disclosure in libcurl 8.8.0 through 8.20.0 allows remote attackers to receive stale proxy passwords on later transfers. The setopt_cptr_proxy path skips freeing stored proxy username and password strings when parsed replacements are NULL, preserving prior values on a reused easy handle. The flaw requires an application to reuse a handle, set and then clear proxy credentials, and perform a later transfer; the curl command-line tool is unaffected.

CVSS severity9.8
Critical
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential disclosure in libcurl 8.8.0 through 8.20.0 allows remote attackers to receive stale proxy passwords on later transfers. The setopt_cptr_proxy path skips freeing stored proxy username and password strings when parsed replacements are NULL, preserving prior values on a reused easy handle. The flaw requires an application to reuse a handle, set and then clear proxy credentials, and perform a later transfer; the curl command-line tool is unaffected.

The record

CVE
CVE-2026-9079
Published
Jul 3, 2026
Updated
Jul 3, 2026
Vendor
curl
Product
curl
Classifications
CWE-522, T1557
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=8.10.0 <=8.10.0
  2. Affected versionversion=8.10.1 <=8.10.1
  3. Affected versionversion=8.11.0 <=8.11.0
  4. Affected versionversion=8.11.1 <=8.11.1
  5. Affected versionversion=8.12.0 <=8.12.0
  6. Affected versionversion=8.12.1 <=8.12.1
  7. Affected versionversion=8.13.0 <=8.13.0
  8. Affected versionversion=8.14.0 <=8.14.0
  9. Affected versionversion=8.14.1 <=8.14.1
  10. Affected versionversion=8.15.0 <=8.15.0
  11. Affected versionversion=8.16.0 <=8.16.0
  12. Affected versionversion=8.17.0 <=8.17.0
  13. Affected versionversion=8.18.0 <=8.18.0
  14. Affected versionversion=8.19.0 <=8.19.0
  15. Affected versionversion=8.20.0 <=8.20.0
  16. Affected versionversion=8.8.0 <=8.8.0
  17. Affected versionversion=8.9.0 <=8.9.0
  18. Affected versionversion=8.9.1 <=8.9.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

curl · curlversion=8.10.0 <=8.10.0; version=8.10.1 <=8.10.1; version=8.11.0 <=8.11.0; version=8.11.1 <=8.11.1; version=8.12.0 <=8.12.0; version=8.12.1 <=8.12.1; 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=8.8.0 <=8.8.0; version=8.9.0 <=8.9.0; version=8.9.1 <=8.9.1

Published CVSS scores

5.9Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
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 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-522Insufficiently Protected Credentials
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

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Your stack

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