CVE-2026-86219Public exploitNetwork attack vector

Authentication bypass via unverified DIGEST-MD5 nonce

Published Sep 6, 2026 · Updated Sep 8, 2026

Authentication bypass in Perl Authen::SASL before 2.2100 allows remote attackers to impersonate users by replaying DIGEST-MD5 responses. The server_step routine validates a digest against the client-supplied nonce without comparing that nonce to the fresh value issued by server_start. Exploitation requires observation of one successful qop=auth exchange for the same service, host, realm, and user.

CVSS severity7.4
High
EPSS probability0.49%
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 Perl Authen::SASL before 2.2100 allows remote attackers to impersonate users by replaying DIGEST-MD5 responses. The server_step routine validates a digest against the client-supplied nonce without comparing that nonce to the fresh value issued by server_start. Exploitation requires observation of one successful qop=auth exchange for the same service, host, realm, and user.

The record

CVE
CVE-2026-86219
Published
Sep 6, 2026
Updated
Sep 8, 2026
Vendor
Erik Huelsmann
Product
Authen::SASL
Classifications
CWE-294, CAPEC-115, T1550
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=0 <2.2100

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Erik Huelsmann · Authen::SASLversion=0 <2.2100

Published CVSS scores

7.4Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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-294Authentication Bypass by Capture-replay
CAPEC-115Authentication Bypass
T1550Use Alternate Authentication Material

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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