CVE-2026-34355
📛 CVE Title
Apache HTTP Server: mod_proxy_html buffer overflow
Description
A buffer overflow in mod_proxy_html in Apache HTTP Server 2.4.67 and earlier allows an attack by an untrusted backend. Users are recommended to upgrade to version 2.4.68, which fixes this issue.
Description (MITRE) cveawg.mitre.org
Pulled from cveawg.mitre.org/api/cve/CVE-2026-34355 on 2026-10-29. Shown when MITRE's text differs from the cvelistV5 mirror.
A buffer overflow in mod_proxy_html in Apache HTTP Server 2.4.67 and earlier allows an attack by an untrusted backend. Users are recommended to upgrade to version 2.4.68, which fixes this issue.
Overview
- State
- —
- Assigner (CNA)
- —
- CVSS severity
- high
- CVSS score
- 7.5 / 10
- CVSS vector
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Effective score
- 7.5 / 10 HIGH source: CNA overview
- MSRC score
- 7.5 / 10 HIGH MS rating: Moderate
- CWE(s)
-
CWE-122 - Reserved
- —
- Published
- 2026-06-09 07:00 UTC
- Last updated
- 2026-06-20 01:43 UTC
- Source
- https://www.tenable.com/cve/CVE-2026-34355
- Linked Threat
- CVE-2026-34355 — CVE-2026-34355
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-06-08 16:16:38 UTC
- NVD last modified
- 2026-07-28 13:18:04 UTC
- NVD CVSS v3.1
- 7.5 / 10 HIGH source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 3.6 / 10
- EPSS score
- 0.0112 (probability of exploitation in next 30 days)
- EPSS percentile
- 62.91% vs all CVEs — higher = more likely to be exploited, as of 2026-08-01
NVD-assigned CWE(s):
CWE-122,
CWE-120
(differs from the CNA list above)
NVD / KEV / EPSS data refreshed 2026-08-01 16:30 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-35097 - Assigner
- apache
- Published
- Jun 8, 2026, 3:20:30 PM
- Updated
- Jul 28, 2026, 12:04:38 PM
- EUVD base score (CVSS 3.1)
-
7.5 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EUVD-reported EPSS
- 1.1200
- Vendors
- Apache Software Foundation
- Products
-
Apache HTTP Server (2.4.0 ≤2.4.67)
- Aliases
-
GHSA-3qgf-pp84-379f
ENISA description: A buffer overflow in mod_proxy_html in Apache HTTP Server 2.4.67 and earlier allows an attack by an untrusted backend. Users are recommended to upgrade to version 2.4.68, which fixes this issue.
EUVD references (1)
Microsoft Security Response Center MSRC
Microsoft's vendor-authoritative record from the Security Update Guide — its own CVSS score, impact, severity rating, exploit assessment, and KB-article fixes. Refreshed 2026-11-03 04:06 UTC (source: CVRF).
- MS severity
- Moderate
- MS CVSS base score
- 7.5 / 10 (temporal 6.9)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U - Release
- 2026-Jun
Affected products — CPE 2.3 (1) NVD
NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.
cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
Vendor references (0)
References embedded in the original CVE record by the assigning CNA.
None in the CVE record.
Web references (5)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- MSRC update guide: CVE-2026-34355 msrc
- http://www.openwall.com/lists/oss-security/2026/06/08/6 tenable:www.openwall.com
- https://httpd.apache.org/security/vulnerabilities_24.html tenable:httpd.apache.org
- https://nvd.nist.gov/vuln/detail/CVE-2026-34355 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-34355 tenable:www.cve.org
NVD-tagged references (10)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- http://www.openwall.com/lists/oss-security/2026/06/08/6 af854a3a-2127-422b-91ae-364da2661108 Mailing List
- https://httpd.apache.org/security/vulnerabilities_24.html security@apache.org Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:25042 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:34109 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:41906 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:42828 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:47046 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/security/cve/CVE-2026-34355 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://bugzilla.redhat.com/show_bug.cgi?id=2486414 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34355.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Remediations (10)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:app.opencve.io
The flaw affects Apache HTTP Server, versions 2.4.67 and earlier, which include the mod_proxy_html module. The vendor recommends upgrading to version 2.4.68 or later to apply the patch that fixes the buffer handling in the proxy module.
2026-06-19 02:37 UTC -
web:cybersecuritynews.com
Microsoft has officially acknowledged a critical zero-day vulnerability in Microsoft Defender, publicly dubbed "RoguePlanet," and confirmed it is actively developing a security patch to address the flaw.
2026-06-19 02:37 UTC -
web:db.gcve.eu
CVE-2026-34355 7.5 (High) ... CWE-122 - Heap-based Buffer Overflow Affected products Known affected1 product Product Identifier Version Remediation Unresolved product id: 17084-1 — None Available References 4 references URL Category
2026-06-19 02:37 UTC -
web:learn.microsoft.com
Windows 11, version 25H2 is now available for all eligible devices. Devices running Home and Pro editions of Windows 11 that are not managed by IT departments will receive the update to Windows 11, version 25H2 through the machine learning-based intelligent rollout.
2026-06-19 02:37 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-06-19 02:37 UTC -
web:security-tracker.debian.org
Vulnerable and fixed packages The table below lists information on source packages.
2026-06-19 02:37 UTC -
web:ubuntu.com
Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things.
2026-06-19 02:37 UTC -
web:www.computerworld.com
Microsoft says it is considering a patch for a zero-day vulnerability, dubbed YellowKey, that allows attackers with access to a Windows device to bypass Bitlocker encryption protection and read ...
2026-06-19 02:37 UTC -
web:www.malwarebytes.com
Microsoft says it's working on a fix for an unpatched Defender vulnerability that can give attackers the highest level of access on Windows.
2026-06-19 02:37 UTC -
web:www.thehackerwire.com
CVE-2026-34355 is a High severity vulnerability (CVSS 7.5). A buffer overflow in mod_proxy_html in Apache HTTP Server 2.4.67 and earlier allows an attack by an untrusted backend.
2026-06-19 02:37 UTC
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