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CVE-2026-21637

A flaw in Node.js TLS error handling allows remote attackers to crash or exhaust resources of a TLS server when `pskCallback` or `ALPNCallback` are in use. Synchronous exceptions thrown during these callbacks bypass standard TLS error handling paths (tlsClientError and error), causing either immediate process termination or silent file descriptor leaks that eventually lead to denial of service. Because these callbacks process attacker-controlled input during the TLS handshake, a remote client ca
Lifecycle PUBLISHED1 preserved revisionFact urn:baitaphish:canonical-cve-fact-revision:v2:412349975a8a46c801fe8804c1b99dc63fcfe1eae73e68e8f5605acf54945a14
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0

Affected products and versions

1 source assertion
{"defaultStatus":"unaffected","product":"node","vendor":"nodejs","versions":[{"lessThanOrEqual":"20.19.6","status":"affected","version":"20.19.6","versionType":"semver"},{"lessThanOrEqual":"22.21.1","status":"affected","version":"22.21.1","versionType":"semver"},{"lessThanOrEqual":"24.12.0","status":"affected","version":"24.12.0","versionType":"semver"},{"lessThanOrEqual":"25.2.1","status":"affected","version":"25.2.1","versionType":"semver"},{"lessThan":"4.*","status":"affected","version":"4.0","versionType":"semver"},{"lessThan":"5.*","status":"affected","version":"5.0","versionType":"semver…
  • cve_program_cvelist_v5affected
    urn:baitaphish:normalized-source-record:v2:2a4e26ff463dbc91cd316dbcef25190838c5d7d8dab64758c4ff442aa6dfff3a · sha256:088b7ccdfc7628d3… · /containers/cna/affected/0

Provider-owned CVSS observations

1 source assertion
{"metric":{"baseScore":5.9,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.0"},"metric_type":"cvssV3_0"}
  • cve_program_cvelist_v5cvss
    urn:baitaphish:normalized-source-record:v2:2a4e26ff463dbc91cd316dbcef25190838c5d7d8dab64758c4ff442aa6dfff3a · sha256:088b7ccdfc7628d3… · /containers/cna/metrics/0/cvssV3_0

CWE assertions

1 source assertion
{"cweId":"CWE-400","description":"CWE-400 Uncontrolled Resource Consumption","lang":"en","type":"CWE"}
  • cve_program_cvelist_v5cwe
    urn:baitaphish:normalized-source-record:v2:2a4e26ff463dbc91cd316dbcef25190838c5d7d8dab64758c4ff442aa6dfff3a · sha256:088b7ccdfc7628d3… · /containers/adp/0/problemTypes/0/descriptions/0

Source references

1 source assertion
{"url":"https://nodejs.org/en/blog/vulnerability/december-2025-security-releases"}
  • cve_program_cvelist_v5reference
    urn:baitaphish:normalized-source-record:v2:2a4e26ff463dbc91cd316dbcef25190838c5d7d8dab64758c4ff442aa6dfff3a · sha256:088b7ccdfc7628d3… · /containers/cna/references/0

Attribution and limitations

  • CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →

Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.

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