How severe is CVE-2026-4602?

CVE-2026-4602 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-4602 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-4602?

CVE-2026-4602 affects Kjur Jsrsasign. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-4602?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-4602 have an EU (EUVD) identifier?

Yes. CVE-2026-4602 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14379.

When was CVE-2026-4602 published?

CVE-2026-4602 was published on 2026-03-23 and last updated on 2026-07-01.

CVE-2026-4602

CVE-2026-4602 is a high-severity vulnerability in Kjur Jsrsasign with a CVSS 3.x base score of 7.5. 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-681.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 7.7
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-14379
Weakness: CWE-681
Affected product: Kjur Jsrsasign
Published: 2026-03-23
Last modified: 2026-07-01

Description

Versions of the package jsrsasign before 11.1.1 are vulnerable to Incorrect Conversion between Numeric Types due to handling negative exponents in ext/jsbn2.js. An attacker can force the computation of incorrect modular inverses and break signature verification by calling modPow with a negative exponent.

Frequently asked questions

What is CVE-2026-4602?: Versions of the package jsrsasign before 11.1.1 are vulnerable to Incorrect Conversion between Numeric Types due to handling negative exponents in ext/jsbn2.js. An attacker can force the computation of incorrect modular inverses and break signature verification by calling modPow with a negative exponent.
How severe is CVE-2026-4602?: CVE-2026-4602 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-4602 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-4602?: CVE-2026-4602 affects Kjur Jsrsasign. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-4602?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-4602 have an EU (EUVD) identifier?: Yes. CVE-2026-4602 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14379.
When was CVE-2026-4602 published?: CVE-2026-4602 was published on 2026-03-23 and last updated on 2026-07-01.

References

Affected products (1)

cpe:2.3:a:kjur:jsrsasign:*:*:*:*:*:node.js:*:*

More vulnerabilities in Kjur Jsrsasign

CVE-2020-14968 — Critical (CVSS 9.8): An issue was discovered in the jsrsasign package before 8.0.17 for Node.js. Its RSASSA-PSS (RSA-PSS) implementation…
CVE-2020-14967 — Critical (CVSS 9.8): An issue was discovered in the jsrsasign package before 8.0.18 for Node.js. Its RSA PKCS1 v1.5 decryption…
CVE-2026-4599 — Critical (CVSS 9.1): Versions of the package jsrsasign from 7.0.0 and before 11.1.1 are vulnerable to Incomplete Comparison with Missing…
CVE-2021-30246 — Critical (CVSS 9.1): In the jsrsasign package through 10.1.13 for Node.js, some invalid RSA PKCS#1 v1.5 signatures are mistakenly recognized…
CVE-2026-4601 — High (CVSS 8.7): Versions of the package jsrsasign before 11.1.1 are vulnerable to Missing Cryptographic Step via the…
CVE-2022-25898 — High (CVSS 7.7): The package jsrsasign before 10.5.25 are vulnerable to Improper Verification of Cryptographic Signature when JWS or JWT…

All CVEs affecting Kjur Jsrsasign →

Other CWE-681 vulnerabilities

CVE-2022-40138 — Critical (CVSS 9.8): An integer conversion error in Hermes bytecode generation, prior to commit 6aa825e480d48127b480b08d13adf70033237097,…
CVE-2021-36357 — Critical (CVSS 9.8): An issue was discovered in OpenPOWER 2.6 firmware. unpack_timestamp() calls le32_to_cpu() for endian conversion of a…
CVE-2021-38187 — Critical (CVSS 9.8): An issue was discovered in the anymap crate through 0.12.1 for Rust. It violates soundness via conversion of a *u8 to a…
CVE-2019-19317 — Critical (CVSS 9.8): lookupName in resolve.c in SQLite 3.30.1 omits bits from the colUsed bitmask in the case of a generated column, which…
CVE-2019-14842 — Critical (CVSS 9.8): Structured reply is a feature of the newstyle NBD protocol allowing the server to send a reply in chunks. A bounds…
CVE-2018-8786 — Critical (CVSS 9.8): FreeRDP prior to version 2.0.0-rc4 contains an Integer Truncation that leads to a Heap-Based Buffer Overflow in…

Browse all CWE-681 vulnerabilities →