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CVE Record

CVE-2026-31812: Quinn affected by unauthenticated remote DoS via panic in QUIC transport parameter parsing

Quinn is a pure-Rust, async-compatible implementation of the IETF QUIC transport protocol. Prior to 0.11.14, a remote, unauthenticated attacker can trigger a denial of service in applications using vulnerable quinn versions by sending a crafted QUIC Initial packet containing malformed quic_transport_parameters. In quinn-proto parsing logic, attacker-controlled varints are decoded with unwrap(), so truncated encodings cause Err(UnexpectedEnd) and panic. This is reachable over the network with a single packet and no prior trust or authentication. This vulnerability is fixed in 0.11.14.

HighCVSS 8.7Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

Internet-reachable services using Quinn before 0.11.14 may be crashed by one malformed QUIC packet. No login or user action is required. The primary business risk is service interruption, not disclosed data theft or modification.

Executive priority

Prioritize internet-facing or business-critical QUIC services for rapid remediation. Because one unauthenticated packet can cause a panic, exposed vulnerable deployments present a credible availability risk even without evidence of active exploitation.

Technical view

Malformed QUIC transport parameters can reach quinn-proto parsing where attacker-controlled variable-length integers are decoded with unwrap(). A truncated encoding returns UnexpectedEnd, causing a panic. The flaw affects Quinn versions before 0.11.14 and is fixed in 0.11.14.

Likely exposure

Exposure is highest for applications directly or transitively using vulnerable Quinn versions and accepting untrusted QUIC traffic. Confirm actual deployed dependency versions and network reachability; package manifests alone may not reflect production binaries.

Exploitation context

The supplied sources describe unauthenticated, low-complexity, single-packet remote denial of service. CVSS 4.0 is 8.7. The CVE is not listed as KEV, and the provided evidence does not establish active exploitation.

Researcher notes

This is CWE-248: an uncaught exceptional condition. The documented impact is availability loss through panic during transport-parameter parsing. The supplied evidence does not claim confidentiality or integrity impact, persistence, code execution, or exploitation in the wild.

Mitigation direction

  • Upgrade direct and transitive Quinn dependencies to version 0.11.14 or later.
  • Rebuild, test, and redeploy every affected application using the corrected dependency.
  • Review applicable Red Hat advisories when Quinn is supplied through Red Hat products.
  • Restrict unnecessary QUIC exposure until affected deployments are updated.

Validation and detection

  • Inventory deployed binaries and dependency lockfiles for Quinn versions below 0.11.14.
  • Identify services accepting untrusted QUIC traffic, including indirectly exposed application components.
  • Confirm rebuilt production artifacts resolve Quinn to version 0.11.14 or later.
  • Review crash, panic, restart, and availability telemetry for suspicious QUIC-triggered failures.
  • Validate availability behavior through authorized regression testing with malformed-input coverage.
Prepared
Confidence
high
Sources
5

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-248: 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.

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cve · low confidence lookup

CVE-2026-31812 mapping review

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

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.7 (4.0)
Known Exploited
No
Published

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

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
9Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: noTechnical 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
8.7CVSS 4.0HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——GitHub_M
5.3CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L3.91.4redhat-SADP

Vulnerability scoring details

Base CVSS 4.0 score

8.7High
CVSS 4.0 vector shape for CVE-2026-31812Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
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-SADPquinn-proto: quinn-proto: Denial of Service via crafted QUIC Initial packet
other:Red Hat severity ratingcvssV3_1
  • 2026-03-10T23:02:15.752Z: Reported to Red Hat.
  • 2026-03-10T21:04:36.812Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
quinn-rsquinn< 0.11.14Listed
Weakness

CWE details

CWE-248

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

CWE-248 · source CWE mapping

Uncaught Exception

Uncaught Exception represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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