CVE-2026-13608Network attack vector

LDAP server impersonation via incomplete SASL handshake

Published Sep 6, 2026 · Updated Sep 8, 2026

Authentication bypass in curl 7.82.0 through 8.21.0 allows man-in-the-middle attackers to impersonate an LDAP server during SASL negotiation. In lib/openldap.c, oldap_state_sasl_resp treated every successful Curl_sasl_continue result outside SASL_INPROGRESS as authenticated, including SASL_IDLE after cancellation. Exploitation requires the OpenLDAP backend and non-TLS LDAP; LDAPS rejects the impostor during certificate validation before this state is reached.

CVSS severityUnavailable
Unscored
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in curl 7.82.0 through 8.21.0 allows man-in-the-middle attackers to impersonate an LDAP server during SASL negotiation. In lib/openldap.c, oldap_state_sasl_resp treated every successful Curl_sasl_continue result outside SASL_INPROGRESS as authenticated, including SASL_IDLE after cancellation. Exploitation requires the OpenLDAP backend and non-TLS LDAP; LDAPS rejects the impostor during certificate validation before this state is reached.

The record

CVE
CVE-2026-13608
Published
Sep 6, 2026
Updated
Sep 8, 2026
Vendor
curl
Product
curl
Classifications
CWE-923, T1557
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

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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=7.82.0 <=7.82.0
  2. Affected versionversion=7.83.0 <=7.83.0
  3. Affected versionversion=7.83.1 <=7.83.1
  4. Affected versionversion=7.84.0 <=7.84.0
  5. Affected versionversion=7.85.0 <=7.85.0
  6. Affected versionversion=7.86.0 <=7.86.0
  7. Affected versionversion=7.87.0 <=7.87.0
  8. Affected versionversion=7.88.0 <=7.88.0
  9. Affected versionversion=7.88.1 <=7.88.1
  10. Affected versionversion=8.0.0 <=8.0.0
  11. Affected versionversion=8.0.1 <=8.0.1
  12. Affected versionversion=8.10.0 <=8.10.0
  13. Affected versionversion=8.10.1 <=8.10.1
  14. Affected versionversion=8.1.0 <=8.1.0
  15. Affected versionversion=8.11.0 <=8.11.0
  16. Affected versionversion=8.11.1 <=8.11.1
  17. Affected versionversion=8.1.1 <=8.1.1
  18. Affected versionversion=8.12.0 <=8.12.0
  19. Affected versionversion=8.12.1 <=8.12.1
  20. Affected versionversion=8.1.2 <=8.1.2
  21. Affected versionversion=8.13.0 <=8.13.0
  22. Affected versionversion=8.14.0 <=8.14.0
  23. Affected versionversion=8.14.1 <=8.14.1
  24. Affected versionversion=8.15.0 <=8.15.0
  25. Affected versionversion=8.16.0 <=8.16.0
  26. Affected versionversion=8.17.0 <=8.17.0
  27. Affected versionversion=8.18.0 <=8.18.0
  28. Affected versionversion=8.19.0 <=8.19.0
  29. Affected versionversion=8.20.0 <=8.20.0
  30. Affected versionversion=8.2.0 <=8.2.0
  31. Affected versionversion=8.21.0 <=8.21.0
  32. Affected versionversion=8.2.1 <=8.2.1
  33. Affected versionversion=8.3.0 <=8.3.0
  34. Affected versionversion=8.4.0 <=8.4.0
  35. Affected versionversion=8.5.0 <=8.5.0
  36. Affected versionversion=8.6.0 <=8.6.0
  37. Affected versionversion=8.7.0 <=8.7.0
  38. Affected versionversion=8.7.1 <=8.7.1
  39. Affected versionversion=8.8.0 <=8.8.0
  40. Affected versionversion=8.9.0 <=8.9.0
  41. Affected versionversion=8.9.1 <=8.9.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

curl · curlversion=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

No CVSS assessment is available in this record.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-923Improper Restriction of Communication Channel to Intended Endpoints
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

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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