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Response snapshot Oct 29, 2026, 18:26 UTC

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VulnerabilityCVE-2026-62374

SD JWT JS is a JavaScript implementation of the Selective Disclosure JWT (SD-JWT) specification.

SD JWT JS is a JavaScript implementation of the Selective Disclosure JWT (SD-JWT) specification. In version 0.19.

At a glance

Exploited
Not known
Severity
7.1 High (CVSS 4.0)
Chance of exploitation
Not estimated
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-62374 (opens a new tab)

What happened

SD JWT JS is a JavaScript implementation of the Selective Disclosure JWT (SD-JWT) specification. In version 0.19.0 and earlier, @sd-jwt/decode, also used by @sd-jwt/core, silently drops a tampered Disclosure whose digest no longer matches the Issuer-signed _sd array and returns a reduced claim set, reporting success while the Issuer signature remains valid.

Both a tampered Disclosure that remains valid JSON and a Disclosure containing invalid UTF-8 bytes reach this silent-drop behavior. In the latter case, the TextDecoder / Buffer decoding path substitutes U+FFFD replacement characters, recovering syntactically valid disclosure data instead of rejecting the malformed input. This violates RFC 9901 section 7.

1 step 5, which requires rejection of unreferenced Disclosures, and section 7.1 step 3 / section 4.2.1, which require rejection of invalid Disclosures. A malicious holder can exploit this omission primitive, including through SDJwtInstance.verify() when key binding is required.

An on-path attacker can also tamper with a Disclosure when the relying party does not enforce key binding; enforced key binding rejects on-path tampering because it invalidates the KB-JWT sd_hash binding. If the relying party defaults to allowing access when a constraining age, role, or restriction claim is absent, the silent claim reduction can change an authorization decision without an error.

Continue reading

This issue is fixed in @sd-jwt/core version 0.20.0; no patched version of the standalone @sd-jwt/decode package is identified.

Scores and how they were measured

CVSS base severity

7.1

Version 4.0As of

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Sources

  1. Primary source

    NVD CVE-2026-62374 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 29). SD JWT JS is a JavaScript implementation of the Selective Disclosure JWT (SD-JWT) specification. (CVE-2026-62374). https://kevwire.com/record/CVE-2026-62374

MLA

"SD JWT JS is a JavaScript implementation of the Selective Disclosure JWT (SD-JWT) specification. (CVE-2026-62374)." KEVWire, 29 Oct. 2026, kevwire.com/record/CVE-2026-62374.

Chicago

KEVWire. "SD JWT JS is a JavaScript implementation of the Selective Disclosure JWT (SD-JWT) specification. (CVE-2026-62374)." Last modified October 29, 2026. https://kevwire.com/record/CVE-2026-62374.

Evidence summary (plain text)

SD JWT JS is a JavaScript implementation of the Selective Disclosure JWT (SD-JWT) specification. (Oct 29, 2026).
SD JWT JS is a JavaScript implementation of the Selective Disclosure JWT (SD-JWT) specification. In version 0.19.0 and earlier, @sd-jwt/decode, also used by @sd-jwt/core, silently drops a tampered Disclosure whose digest no longer matches the Issuer-signed _sd array and returns a reduced claim set, reporting success while the Issuer signature remains valid. Both a tampered Disclosure that remains valid JSON and a Disclosure containing invalid UTF-8 bytes reach this silent-drop behavior.
CVSS 7.1 (version 4.0; evidence as of Oct 29, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-62374).
Sources:
NVD CVE-2026-62374: https://nvd.nist.gov/vuln/detail/CVE-2026-62374
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-29T16:56:00.604Z&lastModEndDate=2026-10-29T18:26:09.730Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-29T16:25:58.627Z&lastModEndDate=2026-10-29T17:55:57.993Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-29T15:55:57.773Z&lastModEndDate=2026-10-29T17:25:56.777Z&resultsPerPage=500&startIndex=0
Record ID: CVE-2026-62374.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 29, 2026, 18:26 UTC. Ingestion is not an independent editorial investigation.

NVD status: Received. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

Record JSON

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Record details

Record detail