CVE-2026-88007: traefik Improper Authentication
Vulnerability summary
CVE-2026-88007 is a critical (CVSS 9.1) Improper Authentication vulnerability in traefik. EPSS estimates a 0.60% chance of exploitation in the next 30 days, higher than 47.6% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 4 · Related 4Timeline
- 10-09-2026PublishedVulnerability first disclosed.
- 10-09-2026Last modifiedVulnerability information updated.
Description
Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.0 until 2.11.57 and 3.7.13, the HTTP/3 entrypoint ConnContext does not call service.AddTransportOnContext, so kerberosRoundTripper uses a shared backend transport instead of a transport dedicated to each frontend connection. With HTTP/3 enabled, a backend using connection-bound NTLM or Negotiate authentication, and backend keep-alive, an unrelated client can reuse a backend connection authenticated for a victim, read victim-only data, and act as that victim without the victim credentials. This issue is fixed in 2.11.57 and 3.7.13.
CVSS metrics
6 scores · 5 sources · 2 versions- OSV · WolfiEcosystem advisory · calculated9.1CriticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- OSV · GoEcosystem advisory · calculated9.1CriticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- OSV · ChainguardEcosystem advisory · calculated9.1CriticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- NVDNIST9.1CriticalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS trend
Probability
0.60%
Chance of exploitation in the next 30 days
Percentile
48%
Versus all other CVEs
30-day change
+0.27 pp
From 0.33% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-287Improper AuthenticationWhen an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
- CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Affected systems
Chainguard2 products
- traefik-3.6All versions (No fix recorded)
- traefik-fips-3.6All versions (No fix recorded)
Github.com/traefik/traefik2 products
- v2≥ 2.11.0, < 2.11.57
- v3≥ 3.0.0, < 3.7.13
Github.com/traefik1 product
- traefikAll versions (No fix recorded)
Traefik1 product
- traefik≥ 2.11.0, < 2.11.57 | ≥ 3.0.0, < 3.7.13 | ≥ 2.8.2, < 2.11.56 | ≥ 3.0.0, < 3.7.12
Wolfi1 product
- traefik-3.6All versions (No fix recorded)
5 vendors · 7 products
References
8 links- github.com/traefik/traefik/security/advisories/GHSA-qqjf-53cj-pwvvX Refsource CONFIRMAdvisoryWEBPatchVendor Advisory
- github.com/traefik/traefik/commit/ff39c47d7459dec9cd8de63c1a4e7aa7315bdc1cX Refsource MISCFIXWEBPatch
- github.com/traefik/traefikPACKAGE