CVE-2026-3634

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 92% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Elevated
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
8%
KEV
Not listed

Published

March 17, 2026

Last Modified

June 17, 2026

Advisory Details (3)

Auto-updated Aug 4, 2026
🔬 Proof of concept available. Patch available. Sources: redhat.
generic🟡 PoC Available

(CVE-2026-3634) libsoup: CRLF injection in `soup_message_headers_set_content_type()` (#485) · Issues · GNOME / libsoup · GitLab

https://gitlab.gnome.org/GNOME/libsoup/-/issues/485
redhat

2445129 – (CVE-2026-3634) CVE-2026-3634 libsoup: libsoup: HTTP header injection and response splitting via CRLF injection in Content-Type header

https://bugzilla.redhat.com/show_bug.cgi?id=2445129
redhat Patch Available

CVE-2026-3634 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-3634

Vendor Advisories for CVE-2026-3634(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(6 across 4 ecosystems)
Debian:12(2)
PackageVulnerable rangeFixed inDependents
libsoup2.42.74.3-1 ... 2.74.3-9 (16 versions)——
libsoup33.2.2-2 ... 3.6.6-1 (35 versions)——
Debian:13(2)
PackageVulnerable rangeFixed inDependents
libsoup2.42.74.3-10.1, 2.74.3-11——
libsoup33.6.5-3 ... 3.6.6-1 (8 versions)——
Debian:11(1)
PackageVulnerable rangeFixed inDependents
libsoup2.42.72.0-2 ... 2.74.3-9 (28 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
libsoup33.6.5-3 ... 3.6.6-1 (8 versions)——

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 27× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-15 03:11 UTCEPSS rescore
  7. 2026-09-13 16:47 UTCEPSS rescore
  8. 2026-09-12 15:01 UTCEPSS rescore
  9. 2026-09-11 14:53 UTCEPSS rescore
  10. 2026-09-11 09:37 UTCEPSS rescore
  11. 2026-09-10 09:34 UTCEPSS rescore
  12. 2026-09-08 22:00 UTCEPSS rescore
  13. 2026-09-07 16:01 UTCEPSS rescore
  14. 2026-09-06 13:47 UTCEPSS rescore
  15. 2026-09-04 05:06 UTCEPSS rescore
  16. 2026-09-02 14:12 UTCEPSS rescore
  17. 2026-09-01 13:53 UTCEPSS rescore
  18. 2026-09-01 04:39 UTCEPSS rescore
  19. 2026-08-30 19:17 UTCEPSS rescore
  20. 2026-08-30 01:22 UTCEPSS rescore
  21. 2026-08-28 21:41 UTCEPSS rescore
  22. 2026-08-27 14:25 UTCEPSS rescore
  23. 2026-08-26 14:46 UTCEPSS rescore
  24. 2026-08-25 13:49 UTCEPSS rescore
  25. 2026-08-23 00:19 UTCEPSS rescore
Show 46 more
  1. 2026-08-21 23:49 UTCEPSS rescore
  2. 2026-08-20 22:55 UTCEPSS rescore
  3. 2026-08-19 17:03 UTCEPSS rescore
  4. 2026-08-18 13:48 UTCEPSS rescore
  5. 2026-08-17 13:47 UTCEPSS rescore
  6. 2026-08-16 14:56 UTCEPSS rescore
  7. 2026-08-16 11:22 UTCEG score recompute
  8. 2026-08-16 11:22 UTCGHSA enrichment
  9. 2026-08-16 02:14 UTCEPSS rescore
  10. 2026-08-15 01:30 UTCEPSS rescore
  11. 2026-08-14 07:29 UTCEG score recompute
  12. 2026-08-14 07:29 UTCGHSA enrichment
  13. 2026-08-13 22:00 UTCEPSS rescore
  14. 2026-08-12 22:16 UTCEG score recompute
  15. 2026-08-12 22:16 UTCGHSA enrichment
  16. 2026-08-12 13:51 UTCEPSS rescore
  17. 2026-08-11 13:43 UTCEPSS rescore
  18. 2026-08-11 04:41 UTCEG score recompute
  19. 2026-08-11 04:41 UTCGHSA enrichment
  20. 2026-08-11 00:00 UTCEPSS rescore
  21. 2026-08-10 05:50 UTCEG score recompute
  22. 2026-08-10 05:50 UTCGHSA enrichment
  23. 2026-08-09 13:46 UTCEPSS rescore
  24. 2026-08-09 07:04 UTCEG score recompute
  25. 2026-08-09 07:04 UTCGHSA enrichment
  26. 2026-08-08 16:37 UTCEPSS rescore
  27. 2026-08-07 17:42 UTCEG score recompute
  28. 2026-08-07 17:42 UTCGHSA enrichment
  29. 2026-08-06 13:46 UTCEPSS rescore
  30. 2026-08-06 01:43 UTCEG score recompute
  31. 2026-08-06 01:43 UTCGHSA enrichment
  32. 2026-08-05 19:17 UTCEPSS rescore
  33. 2026-08-04 15:10 UTCEPSS rescore
  34. 2026-08-04 10:38 UTCEPSS rescore
  35. 2026-08-04 00:52 UTCEG score recompute
  36. 2026-08-04 00:52 UTCGHSA enrichment
  37. 2026-08-03 10:36 UTCEPSS rescore
  38. 2026-08-02 16:50 UTCEG score recompute▲ 2.60
  39. 2026-08-02 16:50 UTCGHSA enrichment
  40. 2026-08-02 02:27 UTCEPSS rescore
  41. 2026-08-01 04:16 UTCEPSS rescore
  42. 2026-07-30 16:28 UTCEPSS rescore
  43. 2026-07-30 01:30 UTCEPSS rescore
  44. 2026-07-27 14:13 UTCEPSS rescore
  45. 2026-07-27 12:52 UTCEG score recompute
  46. 2026-07-27 12:52 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-3634?
CVE-2026-3634 is a medium vulnerability published on March 17, 2026. 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 soupmessageheaderssetcontent_type() function. This vulnerability allows for the injection of arbitrary…
When was CVE-2026-3634 disclosed?
CVE-2026-3634 was first published in the National Vulnerability Database on March 17, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-3634 actively exploited?
CVE-2026-3634 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 91.7% of all scored CVEs.
What is the CVSS score of CVE-2026-3634?
CVE-2026-3634 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-3634?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-3634, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-3634

Explore →

Is Your Infrastructure Affected by CVE-2026-3634?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs