CVE-2026-33635

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.25% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 16.7% of scored records. A rank, not a probability.

NVD base score

4.3 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-03-26 20:30Z7 MO AGO

Last updated

2026-03-30 11:33Z7 MO AGO

Reserved

2026-03-23

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

Medium (CVSS 4.3)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Weaknesses

• CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')Base

Data version

5.2

Document digest

1ecdfb9ef9555936a2eedb3083b61d4395f04e833b45ef10c9372150e8e5fb64

• github.comhttps://github.com/icalendar/icalendar/security/advisories/GHSA-pv9c-9mfh-hvxqx_refsource_CONFIRM
• github.comhttps://github.com/icalendar/icalendar/commit/b8d23b490363ee5fffaec1d269a8618a912ca265x_refsource_MISC
• github.comhttps://github.com/rubysec/ruby-advisory-db/blob/master/gems/icalendar/CVE-2026-33635.ymlx_refsource_MISC