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CVE-2019-18277· NVD / CVE Program· CNA mitre

A flaw was found in HAProxy before 2.0.6.

Noroxi assessment

Priority: Monitor (action score 33/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 10% (FIRST EPSS); higher than 95.6% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: haproxy (Debian:12) 2.0.6-1; haproxy (Debian:9) 1.7.5-2+deb9u1; haproxy (openSUSE:Leap 15.0) 2.0.10+git0.ac198b92-lp150.2.16.1.

Low priority for now. Upgrade to haproxy (Debian:12) 2.0.6-1; haproxy (Debian:9) 1.7.5-2+deb9u1; haproxy (openSUSE:Leap 15.0) 2.0.10+git0.ac198b92-lp150.2.16.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A flaw was found in HAProxy before 2.0.6. In legacy mode, messages featuring a transfer-encoding header missing the "chunked" value were not being correctly rejected. The impact was limited but if combined with the "http-reuse always" setting, it could be used to help construct an HTTP request smuggling attack against a vulnerable component employing a lenient parser that would ignore the content-length header as soon as it saw a transfer-encoding one (even if not entirely valid according to the specification).

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Oct 23, 2019
Updated
Jun 16, 2026
EPSS
10.0% · 95th percentile

Report tools

JSON

Action score

33

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
3 / 30 · 10.0%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
haproxyhaproxy

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • haproxy haproxybefore 2.0.6

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12haproxybefore 2.0.6-12.0.6-1
Debian:9haproxybefore 1.7.5-2+deb9u11.7.5-2+deb9u1
openSUSE:Leap 15.0haproxybefore 2.0.10+git0.ac198b92-lp150.2.16.12.0.10+git0.ac198b92-lp150.2.16.1
openSUSE:Leap 15.1haproxybefore 2.0.10+git0.ac198b92-lp151.2.6.12.0.10+git0.ac198b92-lp151.2.6.1
openSUSE:Tumbleweedhaproxybefore 2.4.4+git0.acb1d0bea-1.22.4.4+git0.acb1d0bea-1.2
Red Hat:enterprise_linux:8::appstreamhaproxybefore 0:1.8.23-3.el80:1.8.23-3.el8
Red Hat:enterprise_linux:8::appstreamhaproxy-debuginfobefore 0:1.8.23-3.el80:1.8.23-3.el8
Red Hat:enterprise_linux:8::appstreamhaproxy-debugsourcebefore 0:1.8.23-3.el80:1.8.23-3.el8
Red Hat:openshift:3.11::el7haproxybefore 0:1.8.23-3.el70:1.8.23-3.el7
Red Hat:openshift:3.11::el7haproxy-debuginfobefore 0:1.8.23-3.el70:1.8.23-3.el7
Red Hat:openshift:3.11::el7haproxy18before 0:1.8.23-3.el70:1.8.23-3.el7
Red Hat:openshift:4.4::el7haproxybefore 0:2.0.13-3.el70:2.0.13-3.el7
Red Hat:openshift:4.4::el7haproxy-debuginfobefore 0:2.0.13-3.el70:2.0.13-3.el7
Red Hat:openshift:4.4::el7haproxy20before 0:2.0.13-3.el70:2.0.13-3.el7
Red Hat:openshift:4.4::el8haproxybefore 0:2.0.13-3.el80:2.0.13-3.el8
Red Hat:openshift:4.4::el8haproxy-debugsourcebefore 0:2.0.13-3.el80:2.0.13-3.el8
Red Hat:openshift:4.4::el8haproxy20before 0:2.0.13-3.el80:2.0.13-3.el8
Red Hat:openshift:4.4::el8haproxy20-debuginfobefore 0:2.0.13-3.el80:2.0.13-3.el8
Red Hat:rhel_software_collections:3::el7rh-haproxy18-haproxybefore 0:1.8.24-2.el70:1.8.24-2.el7
Red Hat:rhel_software_collections:3::el7rh-haproxy18-haproxy-debuginfobefore 0:1.8.24-2.el70:1.8.24-2.el7
Red Hat:rhel_software_collections:3::el7rh-haproxy18-haproxy-syspathsbefore 0:1.8.24-2.el70:1.8.24-2.el7
SUSE:HPE Helion OpenStack 8haproxybefore 1.6.11-11.3.11.6.11-11.3.1
SUSE:Linux Enterprise High Availability Extension 15haproxybefore 2.0.10+git0.ac198b92-3.15.12.0.10+git0.ac198b92-3.15.1
SUSE:Linux Enterprise High Availability Extension 15 SP1haproxybefore 2.0.10+git0.ac198b92-8.8.12.0.10+git0.ac198b92-8.8.1

Same product

haproxy: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-11100In hpack_dht_insert in hpack-tbl.c in the HPACK decoder in HAProxy 1.8 through 2.x before 2.1.4, a remote attacker can write arbitrary bytes
    53Plan
  • CVE-2019-14241HAProxy through 2.0.2 allows attackers to cause a denial of service (ha_panic) via vectors related to htx_manage_client_side_cookies in prot
    51Plan
  • CVE-2021-40346An integer overflow exists in HAProxy 2.0 through 2.5 in htx_add_header that can be exploited to perform an HTTP request smuggling attack, a
    48Plan

Published before and after this one in the same product

  • ← EarlierCVE-2018-20615Mar 21, 2019 · An out-of-bounds read issue was discovered in the HTTP/2 protocol decoder in HAProxy 1.8.x and 1.9.x through 1.9.0 which can result in a cra
    31Monitor
  • ← EarlierCVE-2019-11323May 9, 2019 · HAProxy before 1.9.7 mishandles a reload with rotated keys, which triggers use of uninitialized, and very predictable, HMAC keys.
    23Monitor
  • Later →CVE-2019-19330Nov 27, 2019 · The HTTP/2 implementation in HAProxy before 2.0.10 mishandles headers, as demonstrated by carriage return (CR, ASCII 0xd), line feed (LF, AS
    40Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:haproxy2.0.6-1 · Debian:12Package registry (OSV)
opensuse:haproxy2.0.10+git0.ac198b92-lp150.2.16.1 · openSUSE:Leap 15.0Package registry (OSV)
red hat:haproxy0:1.8.23-3.el7 · Red Hat:openshift:3.11::el7Package registry (OSV)
red hat:haproxy-debuginfo0:1.8.23-3.el7 · Red Hat:openshift:3.11::el7Package registry (OSV)
red hat:haproxy-debugsource0:1.8.23-3.el8 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:haproxy180:1.8.23-3.el7 · Red Hat:openshift:3.11::el7Package registry (OSV)
red hat:haproxy200:2.0.13-3.el7 · Red Hat:openshift:4.4::el7Package registry (OSV)
red hat:haproxy20-debuginfo0:2.0.13-3.el8 · Red Hat:openshift:4.4::el8Package registry (OSV)
red hat:rh-haproxy18-haproxy0:1.8.24-2.el7 · Red Hat:rhel_software_collections:3::el7Package registry (OSV)
red hat:rh-haproxy18-haproxy-debuginfo0:1.8.24-2.el7 · Red Hat:rhel_software_collections:3::el7Package registry (OSV)
red hat:rh-haproxy18-haproxy-syspaths0:1.8.24-2.el7 · Red Hat:rhel_software_collections:3::el7Package registry (OSV)
suse:haproxy2.0.10+git0.ac198b92-3.15.1 · SUSE:Linux Enterprise High Availability Extension 15Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
high · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
High
Availability impact
None

Weakness class (CWE)

CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records