CVE-2023-40225: 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,
Noroxi assessment
Priority: Monitor (action score 29/100)
- 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: 2.1% (FIRST EPSS); higher than 82.1% 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:9) 2.4.22-3.el9_3; haproxy (Debian:11) 2.2.9-2+deb11u6; haproxy (Debian:12) 2.6.12-1+deb12u1.
Low priority for now. Upgrade to haproxy (AlmaLinux:9) 2.4.22-3.el9_3; haproxy (Debian:11) 2.2.9-2+deb11u6; haproxy (Debian:12) 2.6.12-1+deb12u1 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 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, and 2.8.x before 2.8.2 forwards empty Content-Length headers, violating RFC 9110 section 8.6. In uncommon cases, an HTTP/1 server behind HAProxy may interpret the payload as an extra request.
- Published
- Aug 10, 2023
- Updated
- Jun 17, 2026
- EPSS
- 2.1% · 82th percentile
- CWE
- CWE-444
Report tools
Action score
29
Monitor
Low priority for now.
- CVSS
- 28 / 40 · 7.2 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.1%
CISA SSVC decision
- Exploitation
- proof of concept
- 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
- 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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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.
We use this product, ask for helpAffected 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.
| Vendor | Product | CPE |
|---|---|---|
| haproxy | haproxy | cpe:2.3:a:haproxy:haproxy |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- haproxy haproxyup to 2.0.32 inclusive
- haproxy haproxy2.2.0 and later · up to 2.2.30 inclusive
- haproxy haproxy2.4.0 and later · up to 2.4.23 inclusive
- haproxy haproxy2.5.0 and later · before 2.6.15
- haproxy haproxy2.7.0 and later · before 2.7.10
- haproxy haproxy2.8.0 and later · before 2.8.2
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:9 | haproxy | before 2.4.22-3.el9_3 | 2.4.22-3.el9_3 |
| Debian:11 | haproxy | before 2.2.9-2+deb11u6 | 2.2.9-2+deb11u6 |
| Debian:12 | haproxy | before 2.6.12-1+deb12u1 | 2.6.12-1+deb12u1 |
| Debian:13 | haproxy | before 2.6.15-1 | 2.6.15-1 |
| openSUSE:Leap Micro 5.3 | haproxy | before 2.4.22+git0.f8e3218e2-150400.3.16.1 | 2.4.22+git0.f8e3218e2-150400.3.16.1 |
| openSUSE:Tumbleweed | haproxy | before 2.8.2+git0.61a0f576a-2.1 | 2.8.2+git0.61a0f576a-2.1 |
| Red Hat:enterprise_linux:9::appstream | haproxy | before 0:2.4.22-3.el9_3 | 0:2.4.22-3.el9_3 |
| Red Hat:enterprise_linux:9::appstream | haproxy-debuginfo | before 0:2.4.22-3.el9_3 | 0:2.4.22-3.el9_3 |
| Red Hat:enterprise_linux:9::appstream | haproxy-debugsource | before 0:2.4.22-3.el9_3 | 0:2.4.22-3.el9_3 |
| Red Hat:openshift_ironic:4.14::el9 | python-werkzeug | before 0:2.2.3-2.el9 | 0:2.2.3-2.el9 |
| Red Hat:openshift_ironic:4.14::el9 | python3-werkzeug | before 0:2.2.3-2.el9 | 0:2.2.3-2.el9 |
| Red Hat:openshift:4.11::el8 | haproxy | before 0:2.2.24-4.rhaos4.11.el8 | 0:2.2.24-4.rhaos4.11.el8 |
| Red Hat:openshift:4.11::el8 | haproxy-debugsource | before 0:2.2.24-4.rhaos4.11.el8 | 0:2.2.24-4.rhaos4.11.el8 |
| Red Hat:openshift:4.11::el8 | haproxy22 | before 0:2.2.24-4.rhaos4.11.el8 | 0:2.2.24-4.rhaos4.11.el8 |
| Red Hat:openshift:4.11::el8 | haproxy22-debuginfo | before 0:2.2.24-4.rhaos4.11.el8 | 0:2.2.24-4.rhaos4.11.el8 |
| Red Hat:openshift:4.12::el8 | haproxy | before 0:2.2.24-4.rhaos4.12.el8 | 0:2.2.24-4.rhaos4.12.el8 |
| Red Hat:openshift:4.12::el8 | haproxy-debugsource | before 0:2.2.24-4.rhaos4.12.el8 | 0:2.2.24-4.rhaos4.12.el8 |
| Red Hat:openshift:4.12::el8 | haproxy22 | before 0:2.2.24-4.rhaos4.12.el8 | 0:2.2.24-4.rhaos4.12.el8 |
| Red Hat:openshift:4.12::el8 | haproxy22-debuginfo | before 0:2.2.24-4.rhaos4.12.el8 | 0:2.2.24-4.rhaos4.12.el8 |
| Red Hat:openshift:4.13::el8 | haproxy | before 0:2.2.24-4.rhaos4.13.el8 | 0:2.2.24-4.rhaos4.13.el8 |
| Red Hat:openshift:4.13::el8 | haproxy-debugsource | before 0:2.2.24-4.rhaos4.13.el8 | 0:2.2.24-4.rhaos4.13.el8 |
| Red Hat:openshift:4.13::el8 | haproxy22 | before 0:2.2.24-4.rhaos4.13.el8 | 0:2.2.24-4.rhaos4.13.el8 |
| Red Hat:openshift:4.13::el8 | haproxy22-debuginfo | before 0:2.2.24-4.rhaos4.13.el8 | 0:2.2.24-4.rhaos4.13.el8 |
| Red Hat:openshift:4.14::el8 | haproxy | before 0:2.6.13-2.rhaos4.14.el8 | 0:2.6.13-2.rhaos4.14.el8 |
+9
Same product
haproxy: all recordsOther 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 bytes53Plan
- 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 prot51Plan
- 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, a48Plan
Published before and after this one in the same product
- ← EarlierCVE-2023-0836Mar 29, 2023 · An information leak vulnerability was discovered in HAProxy 2.1, 2.2 before 2.2.27, 2.3, 2.4 before 2.4.21, 2.5 before 2.5.11, 2.6 before 2.30Monitor
- ← 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 us30Monitor
- Later →CVE-2023-45539Nov 28, 2023 · HAProxy before 2.8.2 accepts # as part of the URI component, which might allow remote attackers to obtain sensitive information or have unsp32Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| almalinux:haproxy | 2.4.22-3.el9_3 · AlmaLinux:9 | Package registry (OSV) |
| debian:haproxy | 2.6.12-1+deb12u1 · Debian:12 | Package registry (OSV) |
| opensuse:haproxy | 2.4.22+git0.f8e3218e2-150400.3.16.1 · openSUSE:Leap Micro 5.3 | Package registry (OSV) |
| red hat:haproxy | 0:2.6.13-2.rhaos4.14.el8 · Red Hat:openshift:4.14::el8 | Package registry (OSV) |
| red hat:haproxy-debuginfo | 0:2.4.17-6.el9_2.2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:haproxy-debugsource | 0:2.6.13-2.rhaos4.14.el8 · Red Hat:openshift:4.14::el8 | Package registry (OSV) |
| red hat:haproxy22 | 0:2.2.24-4.rhaos4.13.el8 · Red Hat:openshift:4.13::el8 | Package registry (OSV) |
| red hat:haproxy22-debuginfo | 0:2.2.24-4.rhaos4.13.el8 · Red Hat:openshift:4.13::el8 | Package registry (OSV) |
| red hat:haproxy26 | 0:2.6.13-2.rhaos4.14.el8 · Red Hat:openshift:4.14::el8 | Package registry (OSV) |
| red hat:haproxy26-debuginfo | 0:2.6.13-2.rhaos4.14.el8 · Red Hat:openshift:4.14::el8 | Package registry (OSV) |
| red hat:python-werkzeug | 0:2.2.3-2.el9 · Red Hat:openshift_ironic:4.14::el9 | Package registry (OSV) |
| red hat:python3-werkzeug | 0:2.2.3-2.el9 · Red Hat:openshift_ironic:4.14::el9 | Package registry (OSV) |
| suse:haproxy | 2.4.22+git0.f8e3218e2-150400.3.16.1 · SUSE:Linux Enterprise Micro 5.3 | Package 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.
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.
Credits
All researchersFinders, 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
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- Low
- Integrity impact
- Low
- 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:C/C:L/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.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (4 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.