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Full vulnerability report · 2026
CVE-2026-48020High confidence

Traefik StripPrefix Route-Level Auth Bypass via Path Normalization

traefik · traefik

Official source article: GitHub GHSA-XF64-8MW2-4GR2 ↗. 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 2 Sep 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 0.78% 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 ranges3 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/v2< 2.11.482.11.48GitHub advisory ↗upstream repository advisory · 2 Sep 2026
gogithub.com/traefik/traefik/v3< 3.6.193.6.19GitHub advisory ↗upstream repository advisory · 2 Sep 2026
gogithub.com/traefik/traefik/v3>= 3.7.0-ea.1, < 3.7.33.7.3GitHub advisory ↗upstream repository advisory · 2 Sep 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.

2 current
CVE-2026-48020 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitygithub.com/traefik/traefik: Traefik: Authentication bypass in StripPrefix middleware allows unauthorized access to protected paths
4 fixed

The vendor explicitly identifies these products or versions as containing the fix.

  • registry.redhat.io/devspaces/traefik-rhel9@sha256:38a0acf8e97a7d0c6a4c8d6815321e35df6ad35736a7338267ce9b5adb118662_amd64 as a component of Red Hat OpenShift Dev Spaces 3.30
  • registry.redhat.io/devspaces/traefik-rhel9@sha256:8b8f3387a3764beb3d8ad6a027b05f42619ccf33165e733e8dc7b3f135895dc5_ppc64le as a component of Red Hat OpenShift Dev Spaces 3.30
  • registry.redhat.io/devspaces/traefik-rhel9@sha256:b338c1060dd859a8747e0812e176ab266d338aea799becd41e48afc50061fb82_s390x as a component of Red Hat OpenShift Dev Spaces 3.30
  • registry.redhat.io/devspaces/traefik-rhel9@sha256:ba0aebd6b6b6ceb676b6990d5bd9f3b7efe40cedd9407149da92c55435ef7db6_arm64 as a component of Red Hat OpenShift Dev Spaces 3.30
Summary
A flaw was found in Traefik, an HTTP reverse proxy and load balancer. This vulnerability exists in the StripPrefix middleware, allowing an unauthenticated attacker to bypass route-level authentication and authorization. By crafting a request path containing '..' or its percent-encoded form, an attacker can access protected backend paths, such as administrative or internal configuration endpoints, without proper authentication. This could lead to unauthorized information disclosure or modification of sensitive settings.
Remediation
Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
HPESBNW05083 · CSAF 2.0 · revision 1 · finalHPE NetworkingTraefik StripPrefix Route-Level Auth Bypass via Path Normalization (CVE-2026-48020)
1 known affected

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

  • Private 5G Core
Summary
A vulnerability in Traefik could allow an attacker to bypass configured authentication or authorization controls when specific routing configurations are in use. Successful exploitation could permit unauthorized access to protected backend resources.
Remediation
HPE Aruba Networking recommends upgrading Private 5G Core to versions 1.26.1.2 or later. The software updates can be found on My HPE Software Center: - Software and documentation for Customers (available with an order/support contract): https://myenterpriselicense.hpe.com/cwp-ui/software
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-2026-38574

No EUVD known-exploited evidence

Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's StripPrefix middleware that allows an unauthenticated attacker to bypass route-level authentication and authorization. When a public router matches on a PathPrefix rule and applies the StripPrefix middleware, a request path containing .. or its percent-encoded form %2e%2e can match the public route at routing time and then, after the prefix is stripped and the path is normalized, resolve to a path served by a separate, authenticated router. As a result, an attacker can reach protected backend paths — such as admin or internal configuration endpoints — without satisfying the authentication middleware attached to the protected router. This vulnerability is fixed in 2.11.48, 3.6.19, and 3.7.3.

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
7.8 · CVSS 4.0
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 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's StripPrefix middleware that allows an unauthenticated attacker to bypass route-level authentication and authorization. When a public router matches on a PathPrefix rule and applies the StripPrefix middleware, a request path containing .. or its percent-encoded form %2e%2e can match the public route at routing time and then, after the prefix is stripped and the path is normalized, resolve to a path served by a separate, authenticated router. As a result, an attacker can reach protected backend paths — such as admin or internal configuration endpoints — without satisfying the authentication middleware attached to the protected router. This vulnerability is fixed in 2.11.48, 3.6.19, and 3.7.3.

What

Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's StripPrefix middleware that allows an unauthenticated attacker to bypass route-level authentication and authorization. When a public router matches on a PathPrefix rule and applies the StripPrefix middleware, a request path containing .. or its percent-encoded form %2e%2e can match the public route at routing time and then, after the prefix is stripped and the path is normalized, resolve to a path served by a separate, authenticated router. As a result, an attacker can reach protected backend paths — such as admin or internal configuration endpoints — without satisfying the authentication middleware attached to the protected router. This vulnerability is fixed in 2.11.48, 3.6.19, and 3.7.3.

Why

The product requires authentication, but the product has an alternate path or channel that does not require authentication.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's StripPrefix middleware that allows an unauthenticated attacker to bypass route-level authentication and authorization. When a public router matches on a PathPrefix rule and applies the StripPrefix middleware, a request path containing .. or its percent-encoded form %2e%2e can match the public route at routing time and then, after the prefix is stripped and the path is normalized, resolve to a path served by a separate, authenticated router. As a result, an attacker can reach protected backend paths — such as admin or internal configuration endpoints — without satisfying the authentication middleware attached to the protected router. This vulnerability is fixed in 2.11.48, 3.6.19, and 3.7.3.

Why

The product requires authentication, but the product has an alternate path or channel that does not require authentication.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

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 → Authentication Bypass Using an Alternate Path or Channel → cause the confidentiality, integrity or availability impact described by the vendor
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-288 ↗

CWE-288: Authentication Bypass Using an Alternate Path or Channel. The product requires authentication, but the product has an alternate path or channel that does not require authentication.

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:H/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.SIHighSubsequent-system integrity: A successful attack can cause a major loss.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-288Public exploit reference
A

Official authority intelligence

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

ENISA EUVD · EUVD-2026-38574Official EUVD mapping

Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's StripPrefix middleware that allows an unauthenticated attacker to bypass route-level authentication and authorization. When a public router matches on a PathPrefix rule and applies the StripPrefix middleware, a request path containing .. or its percent-encoded form %2e%2e can match the public route at routing time and then, after the prefix is stripped and the path is normalized, resolve to a path served by a separate, authenticated router. As a result, an attacker can reach protected backend paths — such as admin or internal configuration endpoints — without satisfying the authentication middleware attached to the protected router. This vulnerability is fixed in 2.11.48, 3.6.19, and 3.7.3.

Official EUVD record ↗
Canadian Centre for Cyber Security · English · AV26-727HPE security advisory (AV26-727)

On July 21, 2026, HPE published security advisories to address vulnerabilities in the following products. Include was a critical update for the following:

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260624Security Bulletin 24 June 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 24 June 2026, published on 24 June 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0908Multiples 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 une exécution de code arbitraire 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-0690Multiples vulnérabilités dans Traefik

De multiples vulnérabilités ont été découvertes dans Traefik. Elles permettent à un attaquant de provoquer un contournement de la politique de sécurité.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-021318traefikにおける代替パスまたはチャネルを使用した認証回避に関する脆弱性

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2.11.48、3.6.19、および3.7.3より前のバージョンには、認証されていない攻撃者がルートレベルの認証および認可を回避できる、TraefikのStripPrefixミドルウェアに高重大度の脆弱性があります。パスプレフィックスルールに基づいてパブリックルーターがマッチし、StripPrefixミドルウェアを適用すると、リクエストパスに「..」またはそのパーセントエンコード形式「%2e%2e」を含む場合、ルーティング時にパブリックルートにマッチします。その後プレフィックスが削除され、パスが正規化されると、別の認証済みルーターによって提供されるパスに解決されます。その結果、攻撃者は保護されたルーターに添付された認証ミドルウェアを満たすことなく、管理者や内部設定エンドポイントなどの保護されたバックエンドパスにアクセス可能になります。この脆弱性は2.11.48、3.6.19、および3.7.3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
traefik: 3.0.0-beta1, < 3.6.19, 3.7.0-ea.1, < 3.7.3, < 2.11.48
Fixed
Action
Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 23 Jun 2026 · Last source change 2 Sept 2026, 12:04 UTC · CWE-288 · Authentication Bypass Using an Alternate Path or Channel

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-2026-38574
Product sourceCNA
Remediation sourceVendor CSAF · Red Hat Product Security
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
    traefik: >= 3.7.0-ea.1, < 3.7.3, >= 3.0.0-beta1, < 3.6.19, < 2.11.48 · 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
    traefik: >= 3.7.0-ea.1, < 3.7.3, >= 3.0.0-beta1, < 3.6.19, < 2.11.48 · Fixed: RHSA-2026:62260: Red Hat OpenShift Dev Spaces 3.30
    CNA ↗
  2. Vendor guidanceAuthoritative vendor guidance changed: removed vendor advisory: access.redhat.com/RHSA-2026:62260.
    Before
    patch: github.com/GHSA-xf64-8mw2-4gr2 · patch: github.com/v2.11.48 · patch: github.com/v3.6.19 · 3 more references
    After
    patch: github.com/GHSA-xf64-8mw2-4gr2 · patch: github.com/v2.11.48 · patch: github.com/v3.6.19 · 2 more references
    security-advisories@github.com ↗
  3. Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: access.redhat.com/RHSA-2026:62260.
    Before
    patch: github.com/GHSA-xf64-8mw2-4gr2 · patch: github.com/v2.11.48 · patch: github.com/v3.6.19 · 2 more references
    After
    patch: github.com/GHSA-xf64-8mw2-4gr2 · patch: github.com/v2.11.48 · patch: github.com/v3.6.19 · 3 more references
    security-advisories@github.com ↗
  4. Affected versionsThe structured affected or fixed version information changed.
    Before
    >= 3.7.0-ea.1, < 3.7.3; >= 3.0.0-beta1, < 3.6.19; < 2.11.48 · 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
    traefik: >= 3.7.0-ea.1, < 3.7.3, >= 3.0.0-beta1, < 3.6.19, < 2.11.48 · 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.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
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-2026-48020 · cve.blacktree.nl