How severe is CVE-2026-35041?

CVE-2026-35041 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-35041 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-35041?

CVE-2026-35041 affects Nearform Fast-jwt. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-35041?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-35041 have an EU (EUVD) identifier?

Yes. CVE-2026-35041 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20899.

When was CVE-2026-35041 published?

CVE-2026-35041 was published on 2026-04-09 and last updated on 2026-06-17.

CVE-2026-35041

CVE-2026-35041 is a medium-severity vulnerability in Nearform Fast-jwt with a CVSS 3.x base score of 4.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1333.

Key facts

Severity: Medium (CVSS 3.x base score 4.2)
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-20899
Weakness: CWE-1333
Affected product: Nearform Fast-jwt
Published: 2026-04-09
Last modified: 2026-06-17

Description

fast-jwt provides fast JSON Web Token (JWT) implementation. From 5.0.0 to 6.2.0, a denial-of-service condition exists in fast-jwt when the allowedAud verification option is configured using a regular expression. Because the aud claim is attacker-controlled and the library evaluates it against the supplied RegExp, a crafted JWT can trigger catastrophic backtracking in the JavaScript regex engine, resulting in significant CPU consumption during verification. This vulnerability is fixed in 6.2.1.

Frequently asked questions

What is CVE-2026-35041?: fast-jwt provides fast JSON Web Token (JWT) implementation. From 5.0.0 to 6.2.0, a denial-of-service condition exists in fast-jwt when the allowedAud verification option is configured using a regular expression. Because the aud claim is attacker-controlled and the library evaluates it against the supplied RegExp, a crafted JWT can trigger catastrophic backtracking in the JavaScript regex engine, resulting in significant CPU consumption during verification. This vulnerability is fixed in 6.2.1.
How severe is CVE-2026-35041?: CVE-2026-35041 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-35041 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-35041?: CVE-2026-35041 affects Nearform Fast-jwt. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-35041?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-35041 have an EU (EUVD) identifier?: Yes. CVE-2026-35041 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20899.
When was CVE-2026-35041 published?: CVE-2026-35041 was published on 2026-04-09 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nearform:fast-jwt:*:*:*:*:*:node.js:*:*

More vulnerabilities in Nearform Fast-jwt

CVE-2026-35039 — Critical (CVSS 9.1): fast-jwt provides fast JSON Web Token (JWT) implementation. From 0.0.1 to before 6.2.0, setting up a custom…
CVE-2026-34950 — Critical (CVSS 9.1): fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, the publicKeyPemMatcher regex in…
CVE-2026-35042 — High (CVSS 7.5): fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, fast-jwt does not validate the crit…
CVE-2023-48223 — Medium (CVSS 5.9): fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to version 3.3.2, the fast-jwt library does not…
CVE-2026-35040 — Medium (CVSS 5.3): fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.2.1, using certain modifiers on RegExp objects…

All CVEs affecting Nearform Fast-jwt →

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