CVE-2016-4975

MEDIUMNVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

Score 6.1 from GitHub Security Advisory published 2022-05-13. NVD baseline CVSS 6.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
6.1
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • 4 internet-exposed hosts are running an affected version right now
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 20%CVSS: 6.1Exploit: NoneExposed: 4

A fix is available — apply it.

Possible CRLF injection allowing HTTP response splitting attacks for sites which use mod_userdir. This issue was mitigated by changes made in 2.4.25 and 2.2.32 which prohibit CR or LF injection into the "Location" or other outbound header key or value. Fixed in Apache HTTP Server 2.4.25 (Affected 2.4.1-2.4.23). Fixed in Apache HTTP Server 2.2.32 (Affected 2.2.0-2.2.31).

Live · internet exposure

4 internet-exposed hosts are running an affected version of CVE-2016-4975 right now.

across 4 countries (Netherlands, Poland, Taiwan, United States)top: http_server
See the live KEV-Exposure radar →Found passively from public internet-scan data — aggregate, host-redacted.

EchelonGraph is the only CVE feed that fuses live vulnerability intelligence with its own live internet-exposure radar — so you see not just that a CVE is exploited, but how much of the internet is exposed to it right now.

CVSS v3
6.1
EG Score
6.1(medium)
EPSS
97.1%
KEV
Not listed

Published

August 14, 2018

Last Modified

November 21, 2024

References (48)

Vendor Advisories for CVE-2016-4975(1)

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

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatpatch2018-08-16redhat
redhatjbcs-httpd24-openssl-1:1.0.2n-11.jbcs.el62018-07-12redhat
redhatjbcs-httpd24-openssl-1:1.0.2n-11.jbcs.el72018-07-12redhat
redhathttpd-0:2.4.6-45.el7_3.42017-04-12redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

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

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 11× in last 7d / 38× 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. 2026-07-22 14:04 UTCEPSS rescore
  2. 2026-07-21 15:21 UTCEPSS rescore
  3. 2026-07-21 15:21 UTCEPSS rescore
  4. 2026-07-21 06:48 UTCOSV refresh
  5. 2026-07-20 17:03 UTCEPSS rescore
  6. 2026-07-19 02:26 UTCEPSS rescore
  7. 2026-07-19 02:26 UTCEPSS rescore
  8. 2026-07-18 10:00 UTCEPSS rescore
  9. 2026-07-18 10:00 UTCEPSS rescore
  10. 2026-07-16 16:59 UTCEPSS rescore
  11. 2026-07-16 16:59 UTCEPSS rescore
  12. 2026-07-15 16:54 UTCEPSS rescore
  13. 2026-07-15 16:54 UTCEPSS rescore
  14. 2026-07-13 22:26 UTCEPSS rescore
  15. 2026-07-12 05:43 UTCEPSS rescore
  16. 2026-07-12 05:43 UTCEPSS rescore
  17. 2026-07-11 08:23 UTCEPSS rescore
  18. 2026-07-09 19:05 UTCEPSS rescore
  19. 2026-07-08 15:10 UTCEPSS rescore
  20. 2026-07-07 13:42 UTCEPSS rescore
  21. 2026-07-06 16:24 UTCEPSS rescore
  22. 2026-07-06 16:24 UTCEPSS rescore
  23. 2026-07-06 02:20 UTCEPSS rescore
  24. 2026-07-06 02:20 UTCEPSS rescore
  25. 2026-07-05 02:27 UTCEPSS rescore
Show 46 more
  1. 2026-07-04 06:28 UTCEPSS rescore
  2. 2026-07-04 02:26 UTCOSV refresh
  3. 2026-07-01 15:02 UTCEPSS rescore
  4. 2026-06-29 14:03 UTCEPSS rescore
  5. 2026-06-28 14:04 UTCEPSS rescore
  6. 2026-06-28 04:53 UTCEPSS rescore
  7. 2026-06-27 03:05 UTCEPSS rescore
  8. 2026-06-27 03:05 UTCEPSS rescore
  9. 2026-06-25 13:47 UTCEPSS rescore
  10. 2026-06-25 13:47 UTCEPSS rescore
  11. 2026-06-24 14:02 UTCEPSS rescore
  12. 2026-06-24 14:02 UTCEPSS rescore
  13. 2026-06-23 21:30 UTCEPSS rescore
  14. 2026-06-22 14:23 UTCEPSS rescore
  15. 2026-06-21 01:57 UTCEPSS rescore
  16. 2026-06-21 01:57 UTCEPSS rescore
  17. 2026-06-19 19:23 UTCEPSS rescore
  18. 2026-06-19 19:23 UTCEPSS rescore
  19. 2026-06-18 17:50 UTCEPSS rescore
  20. 2026-06-17 17:50 UTCEPSS rescore
  21. 2026-06-17 17:50 UTCEPSS rescore
  22. 2026-06-16 17:50 UTCEPSS rescore
  23. 2026-06-16 17:50 UTCEPSS rescore
  24. 2026-06-15 17:45 UTCEPSS rescore
  25. 2026-06-15 14:43 UTCOSV refresh
  26. 2026-06-12 23:09 UTCEPSS rescore
  27. 2026-06-12 23:09 UTCEPSS rescore
  28. 2026-06-11 13:57 UTCEPSS rescore
  29. 2026-06-10 22:15 UTCEPSS rescore
  30. 2026-06-10 13:18 UTCEPSS rescore
  31. 2026-06-08 14:14 UTCEPSS rescore
  32. 2026-06-07 15:22 UTCEPSS rescore
  33. 2026-06-07 15:22 UTCEPSS rescore
  34. 2026-06-05 22:44 UTCEPSS rescore
  35. 2026-06-05 06:08 UTCEPSS rescore
  36. 2026-06-05 06:08 UTCEPSS rescore
  37. 2026-06-02 20:10 UTCEPSS rescore
  38. 2026-06-01 13:49 UTCEPSS rescore
  39. 2026-06-01 13:49 UTCEPSS rescore
  40. 2026-05-31 00:14 UTCEPSS rescore
  41. 2026-05-29 13:41 UTCEPSS rescore
  42. 2026-05-28 04:07 UTCEG score recompute
  43. 2026-05-28 04:07 UTCVendor advisory
  44. 2026-05-28 04:07 UTCGHSA enrichment
  45. 2026-05-26 07:16 UTCEPSS rescore
  46. 2026-05-24 21:12 UTCOSV refresh

Publicly available exploits

(1 reference)

Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Nucleihttp/cves/2016/CVE-2016-4975.yaml
    First seen Jan 1, 2016

    Apache mod_userdir CRLF injection

    Open source ↗

Frequently asked(5)

What is CVE-2016-4975?
CVE-2016-4975 is a medium vulnerability published on August 14, 2018. Possible CRLF injection allowing HTTP response splitting attacks for sites which use mod_userdir. This issue was mitigated by changes made in 2.4.25 and 2.2.32 which prohibit CR or LF injection into the "Location" or other outbound header key or value. Fixed in Apache HTTP Server 2.4.25 (Affected…
When was CVE-2016-4975 disclosed?
CVE-2016-4975 was first published in the National Vulnerability Database on August 14, 2018, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2016-4975 actively exploited?
CVE-2016-4975 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 97.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2016-4975?
CVE-2016-4975 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2016-4975?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2016-4975, 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

Explore the affected products and dependency analysis for CVE-2016-4975

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