How severe is CVE-2022-41556?

CVE-2022-41556 has a CVSS 3.x base score of 7.5, 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-2022-41556 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2022-41556?

CVE-2022-41556 primarily affects Lighttpd. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2022-41556?

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-2022-41556 published?

CVE-2022-41556 was published on 2022-10-06 and last updated on 2026-06-17.

CVE-2022-41556

CVE-2022-41556 is a high-severity vulnerability in Lighttpd with a CVSS 3.x base score of 7.5. 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-401.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-401
Affected product: Lighttpd
Published: 2022-10-06
Last modified: 2026-06-17

Description

A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of service (connection-slot exhaustion) after a large amount of anomalous TCP behavior by clients. It is related to RDHUP mishandling in certain HTTP/1.1 chunked situations. Use of mod_fastcgi is, for example, affected. This is fixed in 1.4.67.

Frequently asked questions

What is CVE-2022-41556?: A resource leak in gw_backend.c in lighttpd 1.4.56 through 1.4.66 could lead to a denial of service (connection-slot exhaustion) after a large amount of anomalous TCP behavior by clients. It is related to RDHUP mishandling in certain HTTP/1.1 chunked situations. Use of mod_fastcgi is, for example, affected. This is fixed in 1.4.67.
How severe is CVE-2022-41556?: CVE-2022-41556 has a CVSS 3.x base score of 7.5, 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-2022-41556 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-41556?: CVE-2022-41556 primarily affects Lighttpd. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2022-41556?: 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-2022-41556 published?: CVE-2022-41556 was published on 2022-10-06 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:lighttpd:lighttpd:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*

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Other CWE-401 (Missing Release of Memory after Effective Lifetime) vulnerabilities

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CVE-2025-21954 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: netmem: prevent TX of unreadable skbs Currently…
CVE-2024-57947 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_set_pipapo: fix initial map…
CVE-2024-56779 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: nfsd: fix nfs4_openowner leak when concurrent…
CVE-2024-36911 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: hv_netvsc: Don't free decrypted memory In CoCo…

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Threat intelligence

Threat-intel indicators referencing this CVE:

209.97.180.8 (ipv4-addr)
146.190.242.161 (ipv4-addr)
101.13.4.124 (ipv4-addr)
143.110.213.72 (ipv4-addr)
138.68.86.32 (ipv4-addr)
64.226.65.160 (ipv4-addr)
142.93.129.190 (ipv4-addr)
34.14.122.221 (ipv4-addr)