How severe is CVE-2023-45539?

CVE-2023-45539 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.

Is CVE-2023-45539 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-45539?

CVE-2023-45539 affects Haproxy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-45539?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-45539 published?

CVE-2023-45539 was published on 2023-11-28 and last updated on 2026-06-17.

CVE-2023-45539

CVE-2023-45539 is a high-severity vulnerability in Haproxy with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-116.

Key facts

Severity: High (CVSS 3.x base score 8.2)
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-116
Affected product: Haproxy
Published: 2023-11-28
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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 unspecified other impact upon misinterpretation of a path_end rule, such as routing index.html#.png to a static server.
How severe is CVE-2023-45539?: CVE-2023-45539 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2023-45539 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-45539?: CVE-2023-45539 affects Haproxy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-45539?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-45539 published?: CVE-2023-45539 was published on 2023-11-28 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:haproxy:haproxy:*:*:*:*:*:*:*:*

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