How severe is CVE-2021-30641?

CVE-2021-30641 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-30641 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 52% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30641?

CVE-2021-30641 primarily affects Apache Http Server. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-30641?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-30641 published?

CVE-2021-30641 was published on 2021-06-10 and last updated on 2026-06-17.

CVE-2021-30641

CVE-2021-30641 is a medium-severity vulnerability in Apache Http Server with a CVSS 3.x base score of 5.3. Its EPSS exploit-prediction score of 52% places it in the 99th percentile, indicating an elevated likelihood of exploitation.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 52% (99th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Apache Http Server
Published: 2021-06-10
Last modified: 2026-06-17

Description

Apache HTTP Server versions 2.4.39 to 2.4.46 Unexpected matching behavior with 'MergeSlashes OFF'

Frequently asked questions

What is CVE-2021-30641?: Apache HTTP Server versions 2.4.39 to 2.4.46 Unexpected matching behavior with 'MergeSlashes OFF'
How severe is CVE-2021-30641?: CVE-2021-30641 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-30641 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 52% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30641?: CVE-2021-30641 primarily affects Apache Http Server. In total, 10 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-30641?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-30641 published?: CVE-2021-30641 was published on 2021-06-10 and last updated on 2026-06-17.

References

Affected products (10)

cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:*
cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:*
cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*
cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*

More vulnerabilities in Apache Http Server

CVE-2010-0425 — Critical (CVSS 10.0): modules/arch/win32/mod_isapi.c in mod_isapi in the Apache HTTP Server 2.0.37 through 2.0.63, 2.2.0 through 2.2.14, and…
CVE-2005-2700 — Critical (CVSS 10.0): ssl_engine_kernel.c in mod_ssl before 2.8.24, when using "SSLVerifyClient optional" in the global virtual host…
CVE-2004-0492 — Critical (CVSS 10.0): Heap-based buffer overflow in proxy_util.c for mod_proxy in Apache 1.3.25 to 1.3.31 allows remote attackers to cause a…
CVE-2003-0789 — Critical (CVSS 10.0): mod_cgid in Apache before 2.0.48, when using a threaded MPM, does not properly handle CGI redirect paths, which could…
CVE-1999-1293 — Critical (CVSS 10.0): mod_proxy in Apache 1.2.5 and earlier allows remote attackers to cause a denial of service via malformed FTP commands,…
CVE-1999-0926 — Critical (CVSS 10.0): Apache allows remote attackers to conduct a denial of service via a large number of MIME headers.

All CVEs affecting Apache Http Server →

Threat intelligence

Threat-intel indicators referencing this CVE:

46.253.45.10 (ipv4-addr)
223.197.186.7 (ipv4-addr)
211.22.166.107 (ipv4-addr)
202.145.0.61 (ipv4-addr)
20.157.117.15 (ipv4-addr)
186.31.95.163 (ipv4-addr)
181.188.148.74 (ipv4-addr)
157.230.18.133 (ipv4-addr)