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CVE Record

CVE-2026-25949: Traefik: TCP readTimeout bypass via STARTTLS on Postgres

Traefik is an HTTP reverse proxy and load balancer. Prior to 3.6.8, there is a potential vulnerability in Traefik managing STARTTLS requests. An unauthenticated client can bypass Traefik entrypoint respondingTimeouts.readTimeout by sending the 8-byte Postgres SSLRequest (STARTTLS) prelude and then stalling, causing connections to remain open indefinitely, leading to a denial of service. This vulnerability is fixed in 3.6.8.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A remote unauthenticated client can keep vulnerable Traefik connections open indefinitely by abusing STARTTLS handling for Postgres. This can exhaust connection resources and cause service degradation or outage. The issue affects Traefik versions before 3.6.8 and is fixed in 3.6.8.

Executive priority

Prioritize remediation for internet-facing Traefik deployments because the bug can cause outage without authentication. This is not a confidentiality or integrity issue, but availability impact can be material for externally exposed services.

Technical view

Traefik before 3.6.8 can fail to enforce entrypoint respondingTimeouts.readTimeout after a Postgres STARTTLS prelude. A client can stall the connection after the prelude, leaving it open indefinitely. The impact is availability-only denial of service, mapped to CWE-400 and CWE-770 with CVSS 3.1 score 7.5.

Likely exposure

Exposure is most relevant where Traefik versions before 3.6.8 accept network traffic on entrypoints that can receive Postgres STARTTLS-style requests. Internet-facing or broadly reachable Traefik deployments have higher operational risk.

Exploitation context

The source bundle reports unauthenticated network reachability and low attack complexity, but does not cite public exploitation in the wild. KEV status is false, so active exploitation should not be assumed from these sources.

Researcher notes

Evidence supports a STARTTLS handling flaw specific to Traefik connection timeout enforcement. The bundle names the fix release and commit, but does not provide complete downstream product scope beyond Red Hat tracking references. Avoid assuming exploit maturity beyond the stated CVSS and advisory details.

Mitigation direction

  • Upgrade Traefik to version 3.6.8 or later.
  • Review Red Hat advisory RHSA-2026:6192 for packaged product guidance.
  • Restrict network access to affected Traefik entrypoints where feasible.
  • Monitor Traefik connection counts and resource exhaustion symptoms.

Validation and detection

  • Inventory Traefik deployments and confirm no instance is below 3.6.8.
  • Identify entrypoints reachable from untrusted networks.
  • Check configuration using respondingTimeouts.readTimeout for false assurance.
  • Review vendor advisories for environment-specific applicability.
Prepared
Confidence
high
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-400: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cwe · low confidence lookup

CWE-770: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-25949 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
8Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6GitHub_M
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2026-25949Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPgithub.com/traefik/traefik: Traefik: Denial of Service via stalled STARTTLS requests
other:Red Hat severity ratingcvssV3_1
  • 2026-02-12T21:01:13.761Z: Reported to Red Hat.
  • 2026-02-12T20:01:19.600Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
traefiktraefik< 3.6.8Listed
Weakness

CWE details

CWE-400CWE-770

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.