How severe is CVE-2026-33996?

CVE-2026-33996 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-33996 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33996?

CVE-2026-33996 affects Libjwt. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33996?

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

Does CVE-2026-33996 have an EU (EUVD) identifier?

Yes. CVE-2026-33996 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16899.

When was CVE-2026-33996 published?

CVE-2026-33996 was published on 2026-03-27 and last updated on 2026-06-17.

CVE-2026-33996

CVE-2026-33996 is a medium-severity vulnerability in Libjwt with a CVSS 3.x base score of 5.5. 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-476.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v4: 5.8
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-16899
Weakness: CWE-476
Affected product: Libjwt
Published: 2026-03-27
Last modified: 2026-06-17

Description

LibJWT is a C JSON Web Token Library. Starting in version 3.0.0 and prior to version 3.3.0, the JWK parsing for RSA-PSS did not protect against a NULL value when expecting to parse JSON string values. A specially crafted JWK file could exploit this behavior by using integers in places where the code expected a string. This was fixed in v3.3.0. A workaround is available. Users importing keys through a JWK file should not do so from untrusted sources. Use the `jwk2key` tool to check for validity of a JWK file. Likewise, if possible, do not use JWK files with RSA-PSS keys.

Frequently asked questions

What is CVE-2026-33996?: LibJWT is a C JSON Web Token Library. Starting in version 3.0.0 and prior to version 3.3.0, the JWK parsing for RSA-PSS did not protect against a NULL value when expecting to parse JSON string values. A specially crafted JWK file could exploit this behavior by using integers in places where the code expected a string. This was fixed in v3.3.0. A workaround is available. Users importing keys through a JWK file should not do so from untrusted sources. Use the `jwk2key` tool to check for validity of a JWK file. Likewise, if possible, do not use JWK files with RSA-PSS keys.
How severe is CVE-2026-33996?: CVE-2026-33996 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-33996 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33996?: CVE-2026-33996 affects Libjwt. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33996?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-33996 have an EU (EUVD) identifier?: Yes. CVE-2026-33996 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16899.
When was CVE-2026-33996 published?: CVE-2026-33996 was published on 2026-03-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:libjwt:libjwt:*:*:*:*:*:*:*:*

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