LiveActive security incident?Get immediate response
CVE Record

CVE-2026-33814: Infinite loop in HTTP/2 transport when given bad SETTINGS_MAX_FRAME_SIZE in net/http/internal/http2 in golang.org/x/net

When processing HTTP/2 SETTINGS frames, transport will enter an infinite loop of writing CONTINUATION frames if it receives a SETTINGS_MAX_FRAME_SIZE with a value of 0.

HighCVSS 7.5Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This is a denial-of-service issue in Go's HTTP/2 handling. A malicious or broken HTTP/2 peer can send an invalid SETTINGS_MAX_FRAME_SIZE value that makes affected Go transport code loop continuously, consuming availability rather than exposing data.

Executive priority

Treat as high priority for Go-based systems that communicate over HTTP/2 with untrusted peers. The business risk is service disruption, not data theft, based on the supplied evidence.

Technical view

CVE-2026-33814 affects Go net/http and golang.org/x/net/http2 HTTP/2 transport processing. A SETTINGS_MAX_FRAME_SIZE value of 0 can trigger an infinite loop writing CONTINUATION frames. The CVSS 7.5 score reflects network reachability, low complexity, no authentication, and high availability impact.

Likely exposure

Most relevant exposure is Go applications that make HTTP/2 outbound connections using affected net/http or golang.org/x/net/http2 code. Products bundling Go runtimes or vendored x/net/http2 should also be checked. Evidence provided does not identify confidentiality or integrity impact.

Exploitation context

The bundle marks KEV as false and provides no cited evidence of active exploitation. The issue is remotely triggerable in the affected HTTP/2 transport path, but the sources supplied do not include public exploit status or weaponized details.

Researcher notes

Focus review on client-side HTTP/2 transport behavior around SETTINGS frame validation. The affected version metadata in the bundle is sparse, so use GO-2026-4918, the Go announcement, and downstream advisories for precise fixed-version mapping.

Mitigation direction

  • Update Go toolchains according to the Go advisory and announcement.
  • Update golang.org/x/net/http2 where it is vendored or pinned.
  • Apply relevant Red Hat errata for affected packaged products.
  • Check vendor guidance before relying on workarounds.
  • Prioritize internet-reachable or untrusted HTTP/2 client integrations.

Validation and detection

  • Inventory services built with Go net/http or x/net/http2.
  • Review go.mod and vendor trees for golang.org/x/net versions.
  • Confirm runtime or package fixes against GO-2026-4918.
  • Check Red Hat advisories for affected downstream packages.
  • Validate remediation with normal HTTP/2 regression testing.
Prepared
Confidence
medium
Sources
11

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-606: 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-835: 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-2026-33814 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
17Source 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:H3.93.6CISA-ADP
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-2026-33814Attack 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
cvssV3_1other:ssvc
redhat-SADPnet/http/internal/http2: golang: golang.org/x/net: Go HTTP/2: Denial of Service via malformed SETTINGS_MAX_FRAME_SIZE frame
other:Red Hat severity ratingcvssV3_1
  • 2026-05-07T20:01:11.324Z: Reported to Red Hat.
  • 2026-05-07T19:41:17.631Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
golang.org/x/netgolang.org/x/net/http2golang.org/x/net/http2, 0unaffected
Go standard librarynet/httpnet/http, 0, 1.26.0-0unaffected
Weakness

CWE details

CWE-606CWE-835

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

CWE-606 · source CWE mapping

Unchecked Input for Loop Condition

Unchecked Input for Loop Condition represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-835 · source CWE mapping

Loop with Unreachable Exit Condition ('Infinite Loop')

Loop with Unreachable Exit Condition ('Infinite Loop') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs