How severe is CVE-2023-50269?

CVE-2023-50269 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-50269 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 58% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-50269?

CVE-2023-50269 primarily affects Squid-cache Squid. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-50269?

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-2023-50269 published?

CVE-2023-50269 was published on 2023-12-14 and last updated on 2026-06-17.

CVE-2023-50269

CVE-2023-50269 is a high-severity vulnerability in Squid-cache Squid with a CVSS 3.x base score of 8.6. Its EPSS exploit-prediction score of 58% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-674.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 58% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-674
Affected product: Squid-cache Squid
Published: 2023-12-14
Last modified: 2026-06-17

Description

Squid is a caching proxy for the Web. Due to an Uncontrolled Recursion bug in versions 2.6 through 2.7.STABLE9, versions 3.1 through 5.9, and versions 6.0.1 through 6.5, Squid may be vulnerable to a Denial of Service attack against HTTP Request parsing. This problem allows a remote client to perform Denial of Service attack by sending a large X-Forwarded-For header when the follow_x_forwarded_for feature is configured. This bug is fixed by Squid version 6.6. In addition, patches addressing this problem for the stable releases can be found in Squid's patch archives.

Frequently asked questions

What is CVE-2023-50269?: Squid is a caching proxy for the Web. Due to an Uncontrolled Recursion bug in versions 2.6 through 2.7.STABLE9, versions 3.1 through 5.9, and versions 6.0.1 through 6.5, Squid may be vulnerable to a Denial of Service attack against HTTP Request parsing. This problem allows a remote client to perform Denial of Service attack by sending a large X-Forwarded-For header when the follow_x_forwarded_for feature is configured. This bug is fixed by Squid version 6.6. In addition, patches addressing this problem for the stable releases can be found in Squid's patch archives.
How severe is CVE-2023-50269?: CVE-2023-50269 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-50269 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 58% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-50269?: CVE-2023-50269 primarily affects Squid-cache Squid. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-50269?: 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-2023-50269 published?: CVE-2023-50269 was published on 2023-12-14 and last updated on 2026-06-17.

References

Affected products (12)

cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.6:*:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.7:-:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.7:stable1:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.7:stable2:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.7:stable3:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.7:stable4:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.7:stable5:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.7:stable6:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.7:stable7:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.7:stable8:*:*:*:*:*:*
cpe:2.3:a:squid-cache:squid:2.7:stable9:*:*:*:*:*:*

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All CVEs affecting Squid-cache Squid →

Other CWE-674 (Uncontrolled Recursion) vulnerabilities

CVE-2026-43185 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix signededness bug in…
CVE-2023-51803 — Critical (CVSS 9.8): LinuxServer.io Heimdall before 2.5.7 does not prevent use of icons that have non-image data such as the "<?php ?>"…
CVE-2021-41752 — Critical (CVSS 9.8): Stack overflow vulnerability in Jerryscript before commit e1ce7dd7271288be8c0c8136eea9107df73a8ce2 on Oct 20, 2021 due…
CVE-2018-1000618 — Critical (CVSS 9.8): EOSIO/eos eos version after commit f1545dd0ae2b77580c2236fdb70ae7138d2c7168 contains a stack overflow vulnerability in…
CVE-2025-10728 — Critical (CVSS 9.4): When the module renders a Svg file that contains a <pattern> element, it might end up rendering it recursively leading…
CVE-2026-40324 — Critical (CVSS 9.1): Hot Chocolate is an open-source GraphQL server. Prior to versions 12.22.7, 13.9.16, 14.3.1, and 15.1.14, Hot…

Browse all CWE-674 (Uncontrolled Recursion) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

78.39.48.166 (ipv4-addr)
212.58.132.5 (ipv4-addr)
103.200.23.154 (ipv4-addr)
200.89.159.59 (ipv4-addr)
103.54.101.248 (ipv4-addr)
74.113.233.217 (ipv4-addr)
192.3.127.40 (ipv4-addr)