How severe is CVE-2026-3633?

CVE-2026-3633 has a CVSS 3.x base score of 3.9, rated low severity. It is exploitable over network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-3633 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-3633?

CVE-2026-3633 primarily affects Redhat Enterprise Linux. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-3633?

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

Does CVE-2026-3633 have an EU (EUVD) identifier?

Yes. CVE-2026-3633 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-12560.

When was CVE-2026-3633 published?

CVE-2026-3633 was published on 2026-03-17 and last updated on 2026-06-17.

CVE-2026-3633

CVE-2026-3633 is a low-severity vulnerability in Redhat Enterprise Linux with a CVSS 3.x base score of 3.9. 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-93.

Key facts

Severity: Low (CVSS 3.x base score 3.9)
EPSS exploit prediction: 0% (13th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-12560
Weakness: CWE-93
Affected product: Redhat Enterprise Linux
Published: 2026-03-17
Last modified: 2026-06-17

Description

A flaw was found in libsoup. A remote attacker, by controlling the method parameter of the `soup_message_new()` function, could inject arbitrary headers and additional request data. This vulnerability, known as CRLF (Carriage Return Line Feed) injection, occurs because the method value is not properly escaped during request line construction, potentially leading to HTTP request injection.

Frequently asked questions

What is CVE-2026-3633?: A flaw was found in libsoup. A remote attacker, by controlling the method parameter of the `soup_message_new()` function, could inject arbitrary headers and additional request data. This vulnerability, known as CRLF (Carriage Return Line Feed) injection, occurs because the method value is not properly escaped during request line construction, potentially leading to HTTP request injection.
How severe is CVE-2026-3633?: CVE-2026-3633 has a CVSS 3.x base score of 3.9, rated low severity. It is exploitable over network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-3633 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-3633?: CVE-2026-3633 primarily affects Redhat Enterprise Linux. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-3633?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-3633 have an EU (EUVD) identifier?: Yes. CVE-2026-3633 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-12560.
When was CVE-2026-3633 published?: CVE-2026-3633 was published on 2026-03-17 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:gnome:libsoup:-:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*

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