How severe is CVE-2026-3634?

CVE-2026-3634 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-2026-3634 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-3634?

CVE-2026-3634 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-2026-3634?

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

Does CVE-2026-3634 have an EU (EUVD) identifier?

Yes. CVE-2026-3634 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-12561.

When was CVE-2026-3634 published?

CVE-2026-3634 was published on 2026-03-17 and last updated on 2026-06-17.

CVE-2026-3634

CVE-2026-3634 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% (8th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-12561
Weakness: CWE-93
Affected product: Redhat Enterprise Linux
Published: 2026-03-17
Last modified: 2026-06-17

Description

A flaw was found in libsoup. An attacker controlling the value used to set the Content-Type header can inject a Carriage Return Line Feed (CRLF) sequence due to improper input sanitization in the `soup_message_headers_set_content_type()` function. This vulnerability allows for the injection of arbitrary header-value pairs, potentially leading to HTTP header injection and response splitting attacks.

Frequently asked questions

What is CVE-2026-3634?: A flaw was found in libsoup. An attacker controlling the value used to set the Content-Type header can inject a Carriage Return Line Feed (CRLF) sequence due to improper input sanitization in the `soup_message_headers_set_content_type()` function. This vulnerability allows for the injection of arbitrary header-value pairs, potentially leading to HTTP header injection and response splitting attacks.
How severe is CVE-2026-3634?: CVE-2026-3634 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-2026-3634 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-3634?: CVE-2026-3634 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-2026-3634?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-3634 have an EU (EUVD) identifier?: Yes. CVE-2026-3634 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-12561.
When was CVE-2026-3634 published?: CVE-2026-3634 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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