CVE-2026-44579: vercel next.js
Vulnerability summary
CVE-2026-44579 is a high (CVSS 7.5) vulnerability in vercel next.js. EPSS estimates a 0.76% chance of exploitation in the next 30 days, higher than 54.8% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 0 · Related 1Timeline
- 13-05-2026PublishedVulnerability first disclosed.
- 13-08-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · NpmEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · ChainguardEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.76%
Chance of exploitation in the next 30 days
Percentile
55%
Versus all other CVEs
30-day change
+0.02 pp
From 0.75% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
- CWE-833DeadlockThe product contains multiple threads or executable segments that are waiting for each other to release a necessary lock, resulting in deadlock.
Affected systems
Chainguard3 products
- commercial-chainloop-frontendAll versions (No fix recorded)
- keep-ui< 0.51.0-r7
- langfuse-fips-3.152All versions (No fix recorded)
Npm1 product
- next≥ 15.0.0, < 15.5.16 | ≥ 16.0.0, < 16.2.5
Vercel1 product
- next.js≥ 15.0.0, < 15.5.16 | ≥ 16.0.0, < 16.2.5
3 vendors · 5 products
References
13 links- github.com/vercel/next.js/security/advisories/GHSA-mg66-mrh9-m8jxX Refsource CONFIRMWEBAdvisoryMitigationVendor Advisory
- github.com/vercel/next.jsPACKAGE