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NVD / CVE Program· CNA mitre

CVE-2023-45539: HAProxy before 2.8.2 accepts # as part of the URI component, which might allow remote attackers to obtain sensitive information or have unsp

Noroxi assessment

Priority: Monitor (action score 32/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1.5% (FIRST EPSS); higher than 74.5% 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.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: haproxy (AlmaLinux:8) 1.8.27-5.el8_10.1; haproxy (AlmaLinux:9) 2.4.22-3.el9_3; haproxy (Debian:10) 1.8.19-1+deb10u5.

Low priority for now. Upgrade to haproxy (AlmaLinux:8) 1.8.27-5.el8_10.1; haproxy (AlmaLinux:9) 2.4.22-3.el9_3; haproxy (Debian:10) 1.8.19-1+deb10u5 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

HAProxy before 2.8.2 accepts # as part of the URI component, which might allow remote attackers to obtain sensitive information or have unspecified other impact upon misinterpretation of a path_end rule, such as routing index.html#.png to a static server.

HighCVSS 8.2 · v3.1—Proof of concept Fix available
Published
Nov 28, 2023
Updated
Jun 17, 2026
EPSS
1.5% · 74th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

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

Follow CVE-2023-45539

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 2.8.2

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:8haproxybefore 1.8.27-5.el8_10.11.8.27-5.el8_10.1
AlmaLinux:9haproxybefore 2.4.22-3.el9_32.4.22-3.el9_3
Debian:10haproxybefore 1.8.19-1+deb10u51.8.19-1+deb10u5
Debian:11haproxybefore 2.2.9-2+deb11u62.2.9-2+deb11u6
Debian:12haproxybefore 2.6.12-1+deb12u12.6.12-1+deb12u1
Debian:13haproxybefore 2.6.15-12.6.15-1
openSUSE:Leap Micro 5.3haproxybefore 2.4.22+git0.f8e3218e2-150400.3.19.12.4.22+git0.f8e3218e2-150400.3.19.1
Red Hat:enterprise_linux:8::appstreamhaproxybefore 0:1.8.27-5.el8_10.10:1.8.27-5.el8_10.1
Red Hat:enterprise_linux:8::appstreamhaproxy-debuginfobefore 0:1.8.27-5.el8_10.10:1.8.27-5.el8_10.1
Red Hat:enterprise_linux:8::appstreamhaproxy-debugsourcebefore 0:1.8.27-5.el8_10.10:1.8.27-5.el8_10.1
Red Hat:enterprise_linux:9::appstreamhaproxybefore 0:2.4.22-3.el9_30:2.4.22-3.el9_3
Red Hat:enterprise_linux:9::appstreamhaproxy-debuginfobefore 0:2.4.22-3.el9_30:2.4.22-3.el9_3
Red Hat:enterprise_linux:9::appstreamhaproxy-debugsourcebefore 0:2.4.22-3.el9_30:2.4.22-3.el9_3
Red Hat:openshift:4.14::el8haproxybefore 0:2.6.13-4.rhaos4.14.el80:2.6.13-4.rhaos4.14.el8
Red Hat:openshift:4.14::el8haproxy-debugsourcebefore 0:2.6.13-4.rhaos4.14.el80:2.6.13-4.rhaos4.14.el8
Red Hat:openshift:4.14::el8haproxy26before 0:2.6.13-4.rhaos4.14.el80:2.6.13-4.rhaos4.14.el8
Red Hat:openshift:4.14::el8haproxy26-debuginfobefore 0:2.6.13-4.rhaos4.14.el80:2.6.13-4.rhaos4.14.el8
Red Hat:openshift:4.14::el8openshiftbefore 0:4.14.0-202409041843.p0.g03a907c.assembly.stream.el80:4.14.0-202409041843.p0.g03a907c.assembly.stream.el8
Red Hat:openshift:4.14::el8openshift-hyperkubebefore 0:4.14.0-202409041843.p0.g03a907c.assembly.stream.el80:4.14.0-202409041843.p0.g03a907c.assembly.stream.el8
Red Hat:openshift:4.14::el9openshiftbefore 0:4.14.0-202409041843.p0.g03a907c.assembly.stream.el90:4.14.0-202409041843.p0.g03a907c.assembly.stream.el9
Red Hat:openshift:4.14::el9openshift-hyperkubebefore 0:4.14.0-202409041843.p0.g03a907c.assembly.stream.el90:4.14.0-202409041843.p0.g03a907c.assembly.stream.el9
Red Hat:openshift:4.15::el8haproxybefore 0:2.6.13-4.rhaos4.15.el80:2.6.13-4.rhaos4.15.el8
Red Hat:openshift:4.15::el8haproxy-debugsourcebefore 0:2.6.13-4.rhaos4.15.el80:2.6.13-4.rhaos4.15.el8
Red Hat:openshift:4.15::el8haproxy26before 0:2.6.13-4.rhaos4.15.el80:2.6.13-4.rhaos4.15.el8

+44

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-2023-25950Apr 11, 2023 · HTTP request/response smuggling vulnerability in HAProxy version 2.7.0, and 2.6.1 to 2.6.7 allows a remote attacker to alter a legitimate us
    30Monitor
  • ← EarlierCVE-2023-40225Aug 10, 2023 · HAProxy through 2.0.32, 2.1.x and 2.2.x through 2.2.30, 2.3.x and 2.4.x through 2.4.23, 2.5.x and 2.6.x before 2.6.15, 2.7.x before 2.7.10,
    29Monitor
  • Later →CVE-2024-45506Sep 4, 2024 · HAProxy 2.9.x before 2.9.10, 3.0.x before 3.0.4, and 3.1.x through 3.1-dev6 allows a remote denial of service for HTTP/2 zero-copy forwardin
    30Monitor

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
almalinux:haproxy2.4.22-3.el9_3 · AlmaLinux:9Package registry (OSV)
debian:haproxy2.6.12-1+deb12u1 · Debian:12Package registry (OSV)
opensuse:haproxy2.4.22+git0.f8e3218e2-150400.3.19.1 · openSUSE:Leap Micro 5.3Package registry (OSV)
red hat:haproxy0:1.8.27-5.el8_8.1 · Red Hat:rhel_eus:8.8::appstreamPackage registry (OSV)
red hat:haproxy-debuginfo0:1.8.27-5.el8_8.1 · Red Hat:rhel_eus:8.8::appstreamPackage registry (OSV)
red hat:haproxy-debugsource0:1.8.27-5.el8_8.1 · Red Hat:rhel_eus:8.8::appstreamPackage registry (OSV)
red hat:haproxy260:2.6.13-4.rhaos4.15.el8 · Red Hat:openshift:4.15::el8Package registry (OSV)
red hat:haproxy26-debuginfo0:2.6.13-4.rhaos4.15.el8 · Red Hat:openshift:4.15::el8Package registry (OSV)
red hat:podman3:4.4.1-26.2.rhaos4.15.el8 · Red Hat:openshift:4.15::el8Package registry (OSV)
red hat:podman-catatonit3:4.4.1-26.2.rhaos4.15.el8 · Red Hat:openshift:4.15::el8Package registry (OSV)
red hat:podman-catatonit-debuginfo3:4.4.1-26.2.rhaos4.15.el8 · Red Hat:openshift:4.15::el8Package registry (OSV)
red hat:podman-debuginfo3:4.4.1-26.2.rhaos4.15.el8 · Red Hat:openshift:4.15::el8Package registry (OSV)
red hat:podman-debugsource3:4.4.1-26.2.rhaos4.15.el8 · Red Hat:openshift:4.15::el8Package registry (OSV)
red hat:podman-docker3:4.4.1-26.2.rhaos4.15.el8 · Red Hat:openshift:4.15::el8Package registry (OSV)
red hat:podman-gvproxy3:4.4.1-26.2.rhaos4.15.el8 · Red Hat:openshift:4.15::el8Package registry (OSV)
rocky linux:haproxy0:1.8.27-5.el8_10.1 · Rocky Linux:8Package registry (OSV)
suse:haproxy2.0.31-150200.11.26.1 · SUSE:Linux Enterprise High Availability Extension 15 SP2Package registry (OSV)
suse:haproxy2.4.22+git0.f8e3218e2-150400.3.19.1 · SUSE:Linux Enterprise Micro 5.3Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02025-08-27

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.

  1. Published
  2. First PoC+637 d
  3. TodayNov 7, 2026+1074 d

No history yet (it accumulates with the daily EPSS job).

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

Weakness class (CWE)

CWE-116 · Improper Encoding or Escaping of Output

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/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 (3 more)

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

All records