CVE-2026-88878Public exploitNetwork attack vector

Denial of service via missing HTTP/3 read timeout

Published Sep 10, 2026 · Updated Sep 10, 2026

Denial of service in Traefik Proxy 2.8.2 through 2.11.55 and 3.0.0 through 3.7.11 allows remote attackers to exhaust backend connections. The HTTP/3 server omits respondingTimeouts.readTimeout because the TCP connection deadline cannot apply to QUIC streams, leaving slow request bodies unbounded. HTTP/3 must be enabled, after which unauthenticated clients can trickle body bytes to pin one upstream connection per request and interrupt backend service.

CVSS severity5.3
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Traefik Proxy 2.8.2 through 2.11.55 and 3.0.0 through 3.7.11 allows remote attackers to exhaust backend connections. The HTTP/3 server omits respondingTimeouts.readTimeout because the TCP connection deadline cannot apply to QUIC streams, leaving slow request bodies unbounded. HTTP/3 must be enabled, after which unauthenticated clients can trickle body bytes to pin one upstream connection per request and interrupt backend service.

The record

CVE
CVE-2026-88878
Published
Sep 10, 2026
Updated
Sep 10, 2026
Vendor
Traefik Labs
Product
Traefik Proxy
Classifications
CWE-770, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.8.2 <=3.7.13
  2. Affected versionversion=3.0.0 <=3.7.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Traefik Labs · Traefik Proxyversion=2.8.2 <=3.7.13; version=3.0.0 <=3.7.13

Published CVSS scores

5.3GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.003Application Exhaustion Flood

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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