CVE-2026-41181Public exploitNetwork attack vector

Credential disclosure via wholesale error-request header copying

Published May 15, 2026 · Updated May 15, 2026

Information disclosure in Traefik Proxy before 2.11.44, 3.6.15, or 3.7.0-rc.3 allows attackers to expose credentials to error services. The errors middleware's default branch copies the entire original header map when constructing the secondary error-page request. A distinct error service and matching backend status are required; Authorization, Cookie, and other credentials then cross the intended service boundary.

CVSS severity6.9
Medium
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Traefik Proxy before 2.11.44, 3.6.15, or 3.7.0-rc.3 allows attackers to expose credentials to error services. The errors middleware's default branch copies the entire original header map when constructing the secondary error-page request. A distinct error service and matching backend status are required; Authorization, Cookie, and other credentials then cross the intended service boundary.

The record

CVE
CVE-2026-41181
Published
May 15, 2026
Updated
May 15, 2026
Vendor
Traefik Labs
Product
Traefik Proxy
Classifications
CWE-201, T1539, T1528
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 15, 2026CVE publishedPublication date reported by the CVE source.
  2. May 15, 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=< 2.11.43
  2. Affected versionversion=>= 3.0.0-beta1, < 3.6.14
  3. Affected versionversion=>= 3.7.0-rc.0, < 3.7.0-rc.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Traefik Labs · Traefik Proxyversion=< 2.11.43; version=>= 3.0.0-beta1, < 3.6.14; version=>= 3.7.0-rc.0, < 3.7.0-rc.3

Published CVSS scores

5.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
6.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA: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 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-201Insertion of Sensitive Information Into Sent Data
T1539Steal Web Session Cookie
T1528Steal Application Access Token

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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