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CVE.org (no NVD analysis yet)· CNA apache

CVE-2026-63686: Apache HTTP Server: mod_xml2enc crash on charset conversion failure

HighCVSS 7.5 · v3.1—Proof of concept Fix available

Noroxi assessment

Priority: Monitor (action score 30/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.46% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Apache Software Foundation Apache HTTP Server 2.4.69; azl3 httpd 2.4.68-1 on Azure Linux 3.0 2.4.69-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Apache Software Foundation Apache HTTP Server 2.4.69; azl3 httpd 2.4.68-1 on Azure Linux 3.0 2.4.69-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A NULL pointer dereference in mod_xml2enc in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an untrusted backend server to cause a denial of service via a proxied response with a charset whose conversion partially succeeds then fails. Users are recommended to upgrade to version 2.4.69, which fixes this issue.

Published
Oct 1, 2026
Updated
Oct 5, 2026
EPSS
0.4% · 40th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-63686

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

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VendorProduct
apachehttp server

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When you'll hear from us

  • when a new CVE affecting this product is published
  • when a record in your stack enters KEV or is weaponized

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

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Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
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Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • Apache Software Foundation Apache HTTP Server

    • 2.4.0 and later · up to and including 2.4.68affected · semver

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache http server2.4.0 and later · before 2.4.69

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10httpdbefore 2.4.63-13.el10_2.82.4.63-13.el10_2.8
AlmaLinux:10httpd-corebefore 2.4.63-13.el10_2.82.4.63-13.el10_2.8
AlmaLinux:10httpd-develbefore 2.4.63-13.el10_2.82.4.63-13.el10_2.8
AlmaLinux:10httpd-filesystembefore 2.4.63-13.el10_2.82.4.63-13.el10_2.8
AlmaLinux:10httpd-manualbefore 2.4.63-13.el10_2.82.4.63-13.el10_2.8
AlmaLinux:10httpd-toolsbefore 2.4.63-13.el10_2.82.4.63-13.el10_2.8
AlmaLinux:10mod_ldapbefore 2.4.63-13.el10_2.82.4.63-13.el10_2.8
AlmaLinux:10mod_luabefore 2.4.63-13.el10_2.82.4.63-13.el10_2.8
AlmaLinux:10mod_proxy_htmlbefore 1:2.4.63-13.el10_2.81:2.4.63-13.el10_2.8
AlmaLinux:10mod_sessionbefore 2.4.63-13.el10_2.82.4.63-13.el10_2.8
AlmaLinux:10mod_sslbefore 1:2.4.63-13.el10_2.81:2.4.63-13.el10_2.8
AlmaLinux:8httpdbefore 2.4.37-65.module_el8.10.0+4332+2bef2e0d.132.4.37-65.module_el8.10.0+4332+2bef2e0d.13
AlmaLinux:8httpd-develbefore 2.4.37-65.module_el8.10.0+4332+2bef2e0d.132.4.37-65.module_el8.10.0+4332+2bef2e0d.13
AlmaLinux:8httpd-filesystembefore 2.4.37-65.module_el8.10.0+4332+2bef2e0d.132.4.37-65.module_el8.10.0+4332+2bef2e0d.13
AlmaLinux:8httpd-manualbefore 2.4.37-65.module_el8.10.0+4332+2bef2e0d.132.4.37-65.module_el8.10.0+4332+2bef2e0d.13
AlmaLinux:8httpd-toolsbefore 2.4.37-65.module_el8.10.0+4332+2bef2e0d.132.4.37-65.module_el8.10.0+4332+2bef2e0d.13
AlmaLinux:8mod_http2before 1.15.7-10.module_el8.10.0+4270+e5f13fdb.71.15.7-10.module_el8.10.0+4270+e5f13fdb.7
AlmaLinux:8mod_http2before 1.15.7-10.module_el8.10.0+4233+8b7d9181.71.15.7-10.module_el8.10.0+4233+8b7d9181.7
AlmaLinux:8mod_ldapbefore 2.4.37-65.module_el8.10.0+4332+2bef2e0d.132.4.37-65.module_el8.10.0+4332+2bef2e0d.13
AlmaLinux:8mod_mdbefore 1:2.0.8-8.module_el8.10.0+4295+280de5aa.41:2.0.8-8.module_el8.10.0+4295+280de5aa.4
AlmaLinux:8mod_proxy_htmlbefore 1:2.4.37-65.module_el8.10.0+4332+2bef2e0d.131:2.4.37-65.module_el8.10.0+4332+2bef2e0d.13
AlmaLinux:8mod_sessionbefore 2.4.37-65.module_el8.10.0+4332+2bef2e0d.132.4.37-65.module_el8.10.0+4332+2bef2e0d.13
AlmaLinux:8mod_sslbefore 1:2.4.37-65.module_el8.10.0+4332+2bef2e0d.131:2.4.37-65.module_el8.10.0+4332+2bef2e0d.13
AlmaLinux:9httpdbefore 2.4.62-13.el9_8.92.4.62-13.el9_8.9

+67

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-42013Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)KEV
    99Now
  • CVE-2021-41773Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49KEV
    99Now
  • CVE-2024-38475Apache HTTP Server weakness in mod_rewrite when first segment of substitution matches filesystem path.KEV
    96Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-63045Oct 1, 2026 · Apache HTTP Server: mod_proxy_ftp PASV address handling
    30Monitor
  • ← EarlierCVE-2026-63292Oct 1, 2026 · Apache HTTP Server: mod_vhost_alias stack overflow
    30Monitor
  • Later →CVE-2026-63718Oct 1, 2026 · Apache HTTP Server: mod_proxy_uwsgi Transfer-Encoding response smuggling
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Apache Software Foundation Apache HTTP Server2.4.69 · descriptionVendor (CNA)
azl3 httpd 2.4.68-1 on Azure Linux 3.02.4.69-1 · Release NotesMicrosoft (MSRC)
almalinux:httpd2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-core2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-devel2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-filesystem2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-manual2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-tools2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
almalinux:mod_http21.15.7-10.module_el8.10.0+4233+8b7d9181.7 · AlmaLinux:8Package registry (OSV)
almalinux:mod_ldap2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
almalinux:mod_lua2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
almalinux:mod_proxy_html1:2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
almalinux:mod_session2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
almalinux:mod_ssl1:2.4.62-13.el9_8.9 · AlmaLinux:9Package registry (OSV)
alpine:apache22.4.69-r0 · Alpine:v3.21Package registry (OSV)
debian:apache22.4.69-1 · Debian:14Package registry (OSV)
debian:apache22.4.69-1~deb13u1 · Debian:13Package registry (OSV)
debian:apache22.4.71-1~deb12u1 · Debian:12Package registry (OSV)
red hat:httpd0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:httpd-core0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:httpd-devel0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:httpd-filesystem0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:httpd-manual0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:httpd-tools0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:mod_ldap0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:mod_lua0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:mod_proxy_html0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:mod_session0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:mod_ssl0:2.4.69-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
rocky linux:httpd0:2.4.62-13.el9_8.9 · Rocky Linux:9Package registry (OSV)

+10

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×2

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02026-10-31
Proof-of-concept repository on GitHubstars:02026-11-09

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. First PoC+29 d
  4. TodayNov 13, 2026+43 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-467290 days apartApache HTTP Server: mod_heartmonitor denial of service
    30Monitor
  • CVE-2026-29169150 days apartApache HTTP Server: mod_dav_lock indirect lock crash
    30Monitor
  • CVE-2026-33007150 days apartApache HTTP Server: mod_authn_socache crash
    21Monitor

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: patch commit or PR link · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Exploit maturitynone → poc
  2. CVSS— → 7.5
  3. Severity— → high
  4. SSVC exploitation— → none
  5. Exploit maturity— → none
  6. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records