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CVE Record

CVE-2026-44579: Next.js: Denial of Service via connection exhaustion in applications using Cache Components

Next.js is a React framework for building full-stack web applications. From to before 15.5.16 and 16.2.5, applications using Partial Prerendering through the Cache Components feature can be vulnerable to connection exhaustion through crafted POST requests to a server action. In affected configurations, a malicious request can trigger a request-body handling deadlock that leaves connections open for an extended period, consuming file descriptors and server capacity until legitimate users are denied service. This vulnerability is fixed in 15.5.16 and 16.2.5.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

An unauthenticated attacker can send crafted web requests that leave affected Next.js connections stuck open. Enough stalled connections can exhaust file descriptors and server capacity, making the application unavailable to legitimate users. The supplied evidence indicates an availability impact, not data theft or modification.

Executive priority

Prioritize affected internet-facing services because exploitation can interrupt customer access without authentication. Apply the fixed release promptly, beginning with business-critical applications. Systems not using Cache Components should still document configuration evidence before lowering priority.

Technical view

CVE-2026-44579 is a request-body handling deadlock affecting Next.js applications using Partial Prerendering through Cache Components. Crafted POST requests to a server action can retain connections and exhaust resources. Affected releases are 15.0.0–15.5.15 and 16.0.0–16.2.4. The CVSS 3.1 score is 7.5, with CWE-770 and CWE-833 classifications.

Likely exposure

Exposure requires an affected Next.js version and use of Partial Prerendering through Cache Components. Internet-facing server actions increase practical reachability. Applications outside those version ranges, or not using the affected configuration, are not identified as vulnerable by the supplied sources.

Exploitation context

The attack is remotely reachable, requires no privileges or user interaction, and has low stated complexity. Repeated malicious requests could deny service by exhausting connections and file descriptors. The supplied record is not in KEV and provides no evidence of active exploitation; real-world exploitation status is therefore unconfirmed.

Researcher notes

The failure combines uncontrolled resource consumption with a deadlock condition. Assessment should distinguish package presence from exploitable configuration and confirm the running artifact, not only repository manifests. The supplied sources establish affected ranges and fixes but do not establish public proof-of-concept availability, observed attacks, or active exploitation.

Mitigation direction

  • Upgrade Next.js 15 deployments to version 15.5.16 or later.
  • Upgrade Next.js 16 deployments to version 16.2.5 or later.
  • Rebuild and redeploy production artifacts so corrected dependencies are actually running.
  • If upgrades are delayed, review the Vercel advisory for supported interim guidance.

Validation and detection

  • Identify deployed Next.js versions from lockfiles, build metadata, and running artifacts.
  • Confirm whether Cache Components and Partial Prerendering are enabled.
  • Inventory externally reachable server actions in affected applications.
  • Verify production resolves to Next.js 15.5.16, 16.2.5, or later.
  • Monitor prolonged connections, file-descriptor use, and capacity exhaustion without sending disruptive test traffic.
Prepared
Confidence
high
Sources
4

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-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
cwe · low confidence lookup

CWE-833: 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-2026-44579 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
9Source 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-2026-44579Attack 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-SADPnext.js: Next.js: Denial of Service via crafted POST requests to server actions
other:Red Hat severity ratingcvssV3_1
  • 2026-05-13T18:01:32.406Z: Reported to Red Hat.
  • 2026-05-13T17:04:28.388Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
vercelnext.js>= 16.0.0, < 16.2.5, >= 15.0.0, < 15.5.16Listed
Weakness

CWE details

CWE-770CWE-833

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