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NVD / CVE Program· CNA VulnCheck

CVE-2026-88878: Traefik v2.8.2 through v3.6 HTTP/3 Timeout Bypass

MediumCVSS 6.9 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 27/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.42% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: github.com/traefik/traefik/v2 (Go) 2.11.56; github.com/traefik/traefik/v3 (Go) 3.7.12.

Low priority for now. Upgrade to github.com/traefik/traefik/v2 (Go) 2.11.56; github.com/traefik/traefik/v3 (Go) 3.7.12 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Traefik is an HTTP reverse proxy and load balancer. In versions >= v2.8.2 through <= v2.11.55 and >= v3.0.0 through <= v3.7.11, the entryPoints.<name>.transport.respondingTimeouts settings — notably readTimeout, which is enabled by default at 60s — are not applied to the HTTP/3 request path. readTimeout is enforced as a deadline on the underlying TCP connection, which cannot be applied to a QUIC stream, and Traefik's HTTP/3 server is constructed without any timeout. As a result, on entry points with HTTP/3 enabled, an unauthenticated remote client that trickles request body bytes can hold a request open indefinitely and, with it, one upstream connection per request, exhausting bounded backend connection pools and causing denial of service. The issue was introduced in v2.8.2 when a quic-go API change removed the embedded http.Server that carried these timeouts. Fixed in v2.11.56 and v3.7.12.

Published
Sep 10, 2026
Updated
Oct 8, 2026
EPSS
0.4% · 37th percentile

Report tools

JSON

Action score

27

Monitor

Low priority for now.

CVSS
27 / 40 · 6.9 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
6.9
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-88878

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
traefiktraefik

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • traefik traefik

    • 2.8.2 and later · up to and including 3.7.13affected · semver
    • 3.0.0 and later · up to and including 3.7.13affected · semver

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • traefik traefik2.8.2 and later · before 2.11.56
  • traefik traefik3.0.0 and later · before 3.7.12

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Gogithub.com/traefik/traefikfrom 0—
Gogithub.com/traefik/traefik/v2from 2.8.2 · before 2.11.562.11.56
Gogithub.com/traefik/traefik/v3from 3.0.0 · before 3.7.123.7.12

Same product

traefik: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-85595Traefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuth
    38Monitor
  • CVE-2026-88877Traefik v3.7.0 Authentication Bypass via from-to-www-redirect
    37Monitor
  • CVE-2026-88007Traefik HTTP/3 Backend NTLM Connection Reuse
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-88011Sep 10, 2026 · Traefik: ForwardAuth identity spoofing via dot-form header alias
    21Monitor
  • ← EarlierCVE-2026-88012Sep 10, 2026 · Traefik: respondingTimeouts.readTimeout is not applied to HTTP/3, leaving slow-body uploads unbounded
    21Monitor
  • Later →CVE-2026-88879Sep 10, 2026 · Traefik before v2.11.56 Identity Spoofing via Header Alias
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Go:github.com/traefik/traefik/v22.11.56Package registry (OSV)
Go:github.com/traefik/traefik/v33.7.12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-22045238 days apartTraefik's ACME TLS-ALPN fast path lacks timeouts and close on handshake stall
    30Monitor
  • CVE-2026-880120 days apartTraefik: respondingTimeouts.readTimeout is not applied to HTTP/3, leaving slow-body uploads unbounded
    21Monitor
  • CVE-2026-26998189 days apartTraefik: unbounded io.ReadAll on auth server response body causes OOM denial of service(DOS)
    17Monitor

Not on record for this CVE: patch commit or PR link · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-770 · Allocation of Resources Without Limits or Throttling

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records