4.3

CVE-2016-1133: dena h2o

Modified
Published 16-01-2016Last modified 05-08-2024

Vulnerability summary

CVE-2016-1133 is a medium (CVSS 4.3) vulnerability in dena h2o. EPSS estimates a 1.46% chance of exploitation in the next 30 days, higher than 73.5% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 3.7, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
4.3/10
010
Medium · v2.0 (NVD)
EPSS score
1.46%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 16-01-2016
    PublishedVulnerability first disclosed.
  2. 05-08-2024
    Last modifiedVulnerability information updated.

Description

CRLF injection vulnerability in the on_req function in lib/handler/redirect.c in H2O before 1.6.2 and 1.7.x before 1.7.0-beta3 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via a crafted URI.

CVSS metrics

2 scores · 1 source · 2 versions

EPSS trend

Probability

1.46%

Chance of exploitation in the next 30 days

Percentile

74%

Versus all other CVEs

30-day change

No change 0.00 pp

From 1.46% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Dena1 product
  • h2o≤ 1.6.1 | 1.7.0:beta2

1 vendor · 1 product

References

5 links