How severe is CVE-2020-4126?

CVE-2020-4126 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-4126 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-4126?

CVE-2020-4126 primarily affects Hcltech Hcl Inotes. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-4126?

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

When was CVE-2020-4126 published?

CVE-2020-4126 was published on 2020-12-01 and last updated on 2026-06-17.

CVE-2020-4126

CVE-2020-4126 is a medium-severity vulnerability in Hcltech Hcl Inotes with a CVSS 3.x base score of 5.9. 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-311.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 4.3
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-311
Affected product: Hcltech Hcl Inotes
Published: 2020-12-01
Last modified: 2026-06-17

Description

HCL iNotes is susceptible to a sensitive cookie exposure vulnerability. This can allow an unauthenticated remote attacker to capture the cookie by intercepting its transmission within an http session. Fixes are available in HCL Domino and iNotes versions 10.0.1 FP6 and 11.0.1 FP2 and later.

Frequently asked questions

What is CVE-2020-4126?: HCL iNotes is susceptible to a sensitive cookie exposure vulnerability. This can allow an unauthenticated remote attacker to capture the cookie by intercepting its transmission within an http session. Fixes are available in HCL Domino and iNotes versions 10.0.1 FP6 and 11.0.1 FP2 and later.
How severe is CVE-2020-4126?: CVE-2020-4126 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-4126 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-4126?: CVE-2020-4126 primarily affects Hcltech Hcl Inotes. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-4126?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-4126 published?: CVE-2020-4126 was published on 2020-12-01 and last updated on 2026-06-17.

References

https://support.hcltechsw.com/csm?id=kb_article&sysparm_article=KB0085411

Affected products (9)

cpe:2.3:a:hcltech:hcl_inotes:*:*:*:*:*:*:*:*
cpe:2.3:a:hcltech:hcl_inotes:10.0.1:-:*:*:*:*:*:*
cpe:2.3:a:hcltech:hcl_inotes:10.0.1:fixpack1:*:*:*:*:*:*
cpe:2.3:a:hcltech:hcl_inotes:10.0.1:fixpack2:*:*:*:*:*:*
cpe:2.3:a:hcltech:hcl_inotes:10.0.1:fixpack3:*:*:*:*:*:*
cpe:2.3:a:hcltech:hcl_inotes:10.0.1:fixpack4:*:*:*:*:*:*
cpe:2.3:a:hcltech:hcl_inotes:10.0.1:fixpack5:*:*:*:*:*:*
cpe:2.3:a:hcltech:hcl_inotes:11.0.1:-:*:*:*:*:*:*
cpe:2.3:a:hcltech:hcl_inotes:11.0.1:fixpack1:*:*:*:*:*:*

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