How severe is CVE-2020-14967?

CVE-2020-14967 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-14967 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-14967?

CVE-2020-14967 primarily affects Kjur Jsrsasign. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-14967?

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

When was CVE-2020-14967 published?

CVE-2020-14967 was published on 2020-06-22 and last updated on 2026-06-22.

CVE-2020-14967

CVE-2020-14967 is a critical-severity vulnerability in Kjur Jsrsasign with a CVSS 3.x base score of 9.8. 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-119.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 3% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Kjur Jsrsasign
Published: 2020-06-22
Last modified: 2026-06-22

Description

An issue was discovered in the jsrsasign package before 8.0.18 for Node.js. Its RSA PKCS1 v1.5 decryption implementation does not detect ciphertext modification by prepending '\0' bytes to ciphertexts (it decrypts modified ciphertexts without error). An attacker might prepend these bytes with the goal of triggering memory corruption issues.

Frequently asked questions

What is CVE-2020-14967?: An issue was discovered in the jsrsasign package before 8.0.18 for Node.js. Its RSA PKCS1 v1.5 decryption implementation does not detect ciphertext modification by prepending '\0' bytes to ciphertexts (it decrypts modified ciphertexts without error). An attacker might prepend these bytes with the goal of triggering memory corruption issues.
How severe is CVE-2020-14967?: CVE-2020-14967 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-14967 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-14967?: CVE-2020-14967 primarily affects Kjur Jsrsasign. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-14967?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-14967 published?: CVE-2020-14967 was published on 2020-06-22 and last updated on 2026-06-22.

References

Affected products (2)

cpe:2.3:a:kjur:jsrsasign:*:*:*:*:*:node.js:*:*
cpe:2.3:a:netapp:max_data:-:*:*:*:*:*:*:*

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-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…
CVE-2026-4602 — High (CVSS 7.5): Versions of the package jsrsasign before 11.1.1 are vulnerable to Incorrect Conversion between Numeric Types due to…

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