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Full vulnerability report · 2026
CVE-2026-40912High confidence

Traefik: StripPrefixRegex auth bypass via Path/RawPath desync

traefik · traefik

Official source article: GitHub GHSA-6JWX-7VP4-9847 ↗. Check the applicable product and release in the original source.

7.8HighCVSS 4.0
Recommended action
Within 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 15 Jul 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.72% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs traefik traefik and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Open-source package ranges4 source-attributed ranges

These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.

Ecosystem and packageAffected rangeFirst fixed versionEvidence
gogithub.com/traefik/traefik<= 1.7.34Not statedGitHub advisory ↗upstream repository advisory · 21 Jul 2026
gogithub.com/traefik/traefik/v2< 2.11.432.11.43GitHub advisory ↗upstream repository advisory · 21 Jul 2026
gogithub.com/traefik/traefik/v3>= 3.7.0-ea.1, < 3.7.0-rc.23.7.0-rc.2GitHub advisory ↗upstream repository advisory · 21 Jul 2026
gogithub.com/traefik/traefik/v3>= 3.0.0-beta1, < 3.6.143.6.14GitHub advisory ↗upstream repository advisory · 21 Jul 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
HPESBNW05077 · CSAF 2.0 · revision 1 · finalHPE NetworkingStripPrefixRegex auth bypass via Path/RawPath desync
1 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • Private 5G Core
Summary
There is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this dot-segment path in X-Forwarded-Uri, which does not match the protected path patterns and therefore allows the request through. The backend then normalizes the dot-segment to the real path per RFC 3986 and serves the protected content. An unauthenticated attacker can exploit this against any backend that performs dot-segment normalization.
Remediation
HPE Aruba Networking recommends upgrading the software to the following version: - HPE Aruba Networking Private 5G Core 1.26.1.1 and above NOTE: HPE Aruba Networking does not evaluate or patch HPE Aruba Networking Private 5G Core Software versions that have reached their End of Support (EoS) milestone. For more information about HPE Aruba Networking Telco Product Lifecycle and versioning policy, please visit: https://www.hpe.com/psnow/doc/4aa5-5978enw?jumpid=in_pdfviewer-psnow
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-26428

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this dot-segment path in X-Forwarded-Uri, which does not match the protected path patterns and therefore allows the request through. The backend then normalizes the dot-segment to the real path per RFC 3986 and serves the protected content An unauthenticated attacker can exploit this against any backend that performs dot-segment normalization. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.

What

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this dot-segment path in X-Forwarded-Uri, which does not match the protected path patterns and therefore allows the request through. The backend then normalizes the dot-segment to the real path per RFC 3986 and serves the protected content An unauthenticated attacker can exploit this against any backend that performs dot-segment normalization. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.

Why

The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may bypass an access boundary or take over an account.

What

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this dot-segment path in X-Forwarded-Uri, which does not match the protected path patterns and therefore allows the request through. The backend then normalizes the dot-segment to the real path per RFC 3986 and serves the protected content An unauthenticated attacker can exploit this against any backend that performs dot-segment normalization. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.

Why

The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may bypass an access boundary or take over an account.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → Use of Incorrectly-Resolved Name or Reference → bypass an access boundary or take over an account
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-706 ↗

CWE-706: Use of Incorrectly-Resolved Name or Reference. The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCHighSubsequent-system confidentiality: A successful attack can cause a major loss.SILowSubsequent-system integrity: A successful attack can cause a limited loss.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
NetworkUnauthenticatedCWE-706Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

Cyber Security Agency of Singapore · English · CSA-SB-20260506Security Bulletin 06 May 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 06 May 2026, published on 6 May 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0846Multiples vulnérabilités dans les produits HPE Aruba Networking

De multiples vulnérabilités ont été découvertes dans les produits HPE Aruba Networking. Elles permettent à un attaquant de provoquer un déni de service à distance, une atteinte à la confidentialité des données et un contournement de la politique de sécurité.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0490Multiples vulnérabilités dans Traefik

De multiples vulnérabilités ont été découvertes dans Traefik. Elles permettent à un attaquant de provoquer une atteinte à la confidentialité des données et un contournement de la politique de sécurité.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-014234traefikにおける誤って解決された名前や参照の使用に関する脆弱性

TraefikはHTTPリバースプロキシおよびロードバランサーです。バージョン2.11.43、3.6.14、および3.7.0-rc.2より前のバージョンに、高度な深刻度の認証バイパス脆弱性がTraefikのStripPrefixRegexミドルウェアに存在していました。この脆弱性は、ForwardAuth、BasicAuth、またはDigestAuthと組み合わせて使用した場合に発生します。ミドルウェアは正規表現をデコード済みのURLパスに対してマッチさせますが、パーセントエンコードされた生のパスをスライスするために結果のバイト長を使用しています。URLのプレフィックス部分にドット（または複数のドット）が現れると、ストリップ後の生パスはドットセグメント（例：/./admin/secret）になります。ForwardAuthはこのドットセグメントのパスをX-Forwarded-Uriで受け取り、保護されたパスパターンと一致しないため、リクエストを通過させてしまいます。バックエンドはRFC 3986に従ってドットセグメントを実際のパスに正規化し、保護されたコンテンツを提供します。認証されていない攻撃者は、ドットセグメント正規化を行うバックエンドに対してこの脆弱性を悪用できます。この問題はバージョン2.11.43、3.6.14、および3.7.0-rc.2で修正されています。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Private 5G Core
Fixed
Private 5G Core
Action
HPE Aruba Networking recommends upgrading the software to the following version: - HPE Aruba Networking Private 5G Core 1.26.1.1 and above NOTE: HPE Aruba Networking does not evaluate or patch HPE Aruba Networking Private 5G Core Software versions that have reached their End of Support (EoS) milestone. For more information about HPE Aruba Networking Telco Product Lifecycle and versioning policy, please visit: https://www.hpe.com/psnow/doc/4aa5-5978enw?jumpid=in_pdfviewer-psnow
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 30 Apr 2026 · Last source change 15 Jul 2026, 01:00 UTC · CWE-706 · Use of Incorrectly-Resolved Name or Reference

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-26428
Product sourceVendor CSAF · HPE Networking
Remediation sourceVendor CSAF · HPE Networking
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    < 2.11.43; >= 3.0.0-beta1, < 3.6.14; >= 3.7.0-ea.1, < 3.7.0-rc.2 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    < 2.11.43; >= 3.0.0-beta1, < 3.6.14; >= 3.7.0-ea.1, < 3.7.0-rc.2 · Fixed: HPE Aruba Networking recommends upgrading the software to the following version: - HPE Aruba Networking Private 5G Core 1.26.1.1 and above NOTE: HPE Aruba Networking does not evaluate or patch HPE Aruba Networking Private 5G Core Software versions that have reached their End of Support (EoS) milestone. For more information about HPE Aruba Networking Telco Product Lifecycle and versioning policy, please visit: https://www.hpe.com/psnow/doc/4aa5-5978enw?jumpid=in_pdfviewer-psnow
    HPE Networking ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2026-26428↗HPE Networking security advisory↗Public exploit reference · GitHub GHSA-6JWX-7VP4-9847↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-40912 · cve.blacktree.nl