Answer in brief
CVE-2026-32305 records a Medium severity (CVSS 5.3) vulnerability in Traefik mTLS bypass via fragmented ClientHello SNI extraction failure. The current sources do not mark it as known exploited. The current feed maps traefik/traefik (generic), github.com/traefik/traefik (go), github.com/traefik/traefik/v2 (go), github.com/traefik/traefik/v3 (go) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps traefik/traefik (generic), github.com/traefik/traefik (go), github.com/traefik/traefik/v2 (go), github.com/traefik/traefik/v3 (go) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| traefik/traefikgeneric | < 2.11.41 || >= 3.0.0-beta1, < 3.6.11 || >= 3.7.0-ea.1, < 3.7.0-ea.2 | Not reported |
| github.com/traefik/traefikgo | >=0 | Not reported |
| github.com/traefik/traefik/v2go | >=0 <2.11.41 | 2.11.41 |
| github.com/traefik/traefik/v3go | >=3.7.0-ea.1 <3.7.0-ea.2 | 3.7.0-ea.2 |
| github.com/traefik/traefik/v3go | >=0 <3.6.11 | 3.6.11 |
| github.com/traefik/traefik/v3go | >=0 <3.6.11 >=3.7.0-ea.1 <3.7.0-ea.2 | 3.6.11, 3.7.0-ea.2 |
Published upstream
Mar 20, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 15, 2026
Traefik is an HTTP reverse proxy and load balancer. Versions 2.11.40 and below, 3.0.0-beta1 through 3.6.11, and 3.7.0-ea.1 are vulnerable to mTLS bypass through the TLS SNI pre-sniffing logic related to fragmented ClientHello packets. When a TLS ClientHello is fragmented across multiple records, Traefik's SNI extraction may fail with an EOF and return an empty SNI. The TCP router then falls back to the default TLS configuration, which does not require client certificates by default. This allows an attacker to bypass route-level mTLS enforcement and access services that should require mutual TLS authentication. This issue is patched in versions 2.11.41, 3.6.11 and 3.7.0-ea.2.
Quoted source text, attributed separately from HOL analysis.