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Full vulnerability report · 2022
CVE-2022-26377High confidence

mod_proxy_ajp: Possible request smuggling

Apache Software Foundation · Apache HTTP Server

7.5HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 6 Oct 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 21.08% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Apache Software Foundation Apache HTTP Server and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Alpine, Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

7 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · mainapache2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.4.54-r0Alpine Security Database ↗Source updated 6 Oct 2026
Alpine v3.22v3.22 · mainapache2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.4.54-r0Alpine Security Database ↗Source updated 6 Oct 2026
Alpine v3.21v3.21 · mainapache2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.4.54-r0Alpine Security Database ↗Source updated 6 Oct 2026
Debian trixietrixie · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.54-1Debian Security Tracker ↗Source updated 7 Oct 2026
Debian bookwormbookworm · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.54-1Debian Security Tracker ↗Source updated 7 Oct 2026
Debian forkyforky · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.54-1Debian Security Tracker ↗Source updated 7 Oct 2026
Debian sidsid · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.54-1Debian Security Tracker ↗Source updated 7 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2022-26377 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityhttpd: mod_proxy_ajp: Possible request smuggling
17 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • httpd as a component of Red Hat Enterprise Linux 6
  • httpd-devel as a component of Red Hat Enterprise Linux 6
  • httpd-manual as a component of Red Hat Enterprise Linux 6
  • httpd-tools as a component of Red Hat Enterprise Linux 6
  • httpd.src as a component of Red Hat Enterprise Linux 6
  • mod_ssl as a component of Red Hat Enterprise Linux 6
  • httpd as a component of Red Hat Enterprise Linux 7
  • httpd-devel as a component of Red Hat Enterprise Linux 7
  • httpd-manual as a component of Red Hat Enterprise Linux 7
  • httpd-tools as a component of Red Hat Enterprise Linux 7
  • httpd.src as a component of Red Hat Enterprise Linux 7
  • mod_ldap as a component of Red Hat Enterprise Linux 7
Summary
An HTTP request smuggling vulnerability was found in the mod_proxy_ajp module of httpd. This flaw allows an attacker to smuggle requests to the AJP server, where it forwards requests.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Applications using the APR libraries, such as httpd, must be restarted for this update to take effect. After installing the updated packages, the httpd daemon will be restarted automatically.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2022-30936

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server allows an attacker to smuggle requests to the AJP server it forwards requests to. This issue affects Apache HTTP Server Apache HTTP Server 2.4 version 2.4.53 and prior versions.

What

Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server allows an attacker to smuggle requests to the AJP server it forwards requests to. This issue affects Apache HTTP Server Apache HTTP Server 2.4 version 2.4.53 and prior versions.

Why

The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server allows an attacker to smuggle requests to the AJP server it forwards requests to. This issue affects Apache HTTP Server Apache HTTP Server 2.4 version 2.4.53 and prior versions.

Why

The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-444 ↗

CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling'). The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-444
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2024-1591Juniper JUNOS: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Juniper JUNOS ausnutzen, um einen Denial of Service zu verursachen, Informationen offenzulegen, Privilegien zu erweitern und Sicherheitsmechanismen inklusive zu umgehen.

Official advisory ↗
BSI · German · WID-SEC-2022-0192Apache HTTP Server: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Apache HTTP Server ausnutzen, um falsche Informationen darzustellen, vertrauliche Informationen offenzulegen, einen Denial of Service Zustand herzustellen und Sicherheitsmaßnahmen zu umgehen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20220615Security Bulletin 15 Jun 2022

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 15 Jun 2022, published on 15 June 2022. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0575Multiples vulnérabilités dans les produits Juniper Networks

ord?id=CVE-2022-22823 Référence CVE CVE-2022-22824 https://www.cve.org/CVERecord?id=CVE-2022-22824 Référence CVE CVE-2022-23852 https://www.cve.org/CVERecord?id=CVE-2022-23852 Référence CVE CVE-2022-23943 https://www.cve.org/CVERecord?id=CVE-2022-23943 Référence CVE CVE-2022-25147 https://www.cve.org/CVERecord?id=CVE-2022-25147 Référence CVE CVE-2022-25235 https://www.cve.org/CVERecord?id=CVE-2022-25235 Référence CVE CVE-2022-25236 https://www.cve.org/CVERecord?id=CVE-2022-25236 Référence CVE CVE-2022-2526 https://www.cve.org/CVERecord?id=CVE-2022-2526 Référence CVE CVE-2022-25315 https://www.cve.org/CVERecord?id=CVE-2022-25315 Référence CVE CVE-2022-26377 https://www.cve.org/CVERecord?id=CVE-2022-26377 Référence CVE CVE-2022-28330 https://www.cve.org/CVERecord?id=CVE-2022-28330 Référence CVE CVE-2022-28614 https://www.cve.org/CVERecord?id=CVE-2022-28614 Référence CVE CVE-2022-28615 https://www.cve.org/CVERecord?id=CVE-2022-28615 Référence CVE CVE-2022-29167 https://www.cve.org/CVERecord?id=CVE-2022-29167 Référence CVE CVE-2022-29404 https://www.cve.org/CVERecord?id=CVE-2022-29404 Référence CVE CVE-2022-30522 https://www.cve.org/CVERecord?id=CVE-2022-30522 Référence CVE CVE-2022-30556 https://www.cve.org/CVERecord?id=CVE-2022-30556 Référence CVE CVE-2022-31813 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0506Multiples vulnérabilités dans Juniper Secure Analytics

VERecord?id=CVE-2021-3753 Référence CVE CVE-2021-41043 https://www.cve.org/CVERecord?id=CVE-2021-41043 Référence CVE CVE-2021-4204 https://www.cve.org/CVERecord?id=CVE-2021-4204 Référence CVE CVE-2021-43618 https://www.cve.org/CVERecord?id=CVE-2021-43618 Référence CVE CVE-2021-43818 https://www.cve.org/CVERecord?id=CVE-2021-43818 Référence CVE CVE-2021-43975 https://www.cve.org/CVERecord?id=CVE-2021-43975 Référence CVE CVE-2022-0500 https://www.cve.org/CVERecord?id=CVE-2022-0500 Référence CVE CVE-2022-2127 https://www.cve.org/CVERecord?id=CVE-2022-2127 Référence CVE CVE-2022-23222 https://www.cve.org/CVERecord?id=CVE-2022-23222 Référence CVE CVE-2022-26377 https://www.cve.org/CVERecord?id=CVE-2022-26377 Référence CVE CVE-2022-26691 https://www.cve.org/CVERecord?id=CVE-2022-26691 Référence CVE CVE-2022-28388 https://www.cve.org/CVERecord?id=CVE-2022-28388 Référence CVE CVE-2022-3094 https://www.cve.org/CVERecord?id=CVE-2022-3094 Référence CVE CVE-2022-3545 https://www.cve.org/CVERecord?id=CVE-2022-3545 Référence CVE CVE-2022-3565 https://www.cve.org/CVERecord?id=CVE-2022-3565 Référence CVE CVE-2022-3594 https://www.cve.org/CVERecord?id=CVE-2022-3594 Référence CVE CVE-2022-3640 https://www.cve.org/CVERecord?id=CVE-2022-3640 Référence CVE CVE-2022-36402 https://www.cve.org/CVERecord?id=CVE-2022-3

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0262Multiples vulnérabilités dans les produits IBM

cord?id=CVE-2020-1968 Référence CVE CVE-2020-25659 https://www.cve.org/CVERecord?id=CVE-2020-25659 Référence CVE CVE-2020-27783 https://www.cve.org/CVERecord?id=CVE-2020-27783 Référence CVE CVE-2020-28493 https://www.cve.org/CVERecord?id=CVE-2020-28493 Référence CVE CVE-2020-36242 https://www.cve.org/CVERecord?id=CVE-2020-36242 Référence CVE CVE-2021-28957 https://www.cve.org/CVERecord?id=CVE-2021-28957 Référence CVE CVE-2021-43818 https://www.cve.org/CVERecord?id=CVE-2021-43818 Référence CVE CVE-2022-2127 https://www.cve.org/CVERecord?id=CVE-2022-2127 Référence CVE CVE-2022-25647 https://www.cve.org/CVERecord?id=CVE-2022-25647 Référence CVE CVE-2022-26377 https://www.cve.org/CVERecord?id=CVE-2022-26377 Référence CVE CVE-2022-36760 https://www.cve.org/CVERecord?id=CVE-2022-36760 Référence CVE CVE-2022-40303 https://www.cve.org/CVERecord?id=CVE-2022-40303 Référence CVE CVE-2022-40304 https://www.cve.org/CVERecord?id=CVE-2022-40304 Référence CVE CVE-2022-4304 https://www.cve.org/CVERecord?id=CVE-2022-4304 Référence CVE CVE-2022-48564 https://www.cve.org/CVERecord?id=CVE-2022-48564 Référence CVE CVE-2022-48565 https://www.cve.org/CVERecord?id=CVE-2022-48565 Référence CVE CVE-2023-0215 https://www.cve.org/CVERecord?id=CVE-2023-0215 Référence CVE CVE-2023-0286 https://www.cve.org/CVERecord?id=CVE-2

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-742Multiples vulnérabilités dans Qnap QTS

De multiples vulnérabilités ont été découvertes dans Qnap QTS. Certaines d'entre elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur, un déni de service à distance et une atteinte à l'intégrité des données.

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-561Multiples vulnérabilités dans IBM HTTP Server

De multiples vulnérabilités ont été découvertes dans IBM HTTP Server. Elles permettent à un attaquant de provoquer un déni de service à distance, un contournement de la politique de sécurité et une atteinte à la confidentialité des données.

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-531Multiples vulnérabilités dans Apache HTTP Server

De multiples vulnérabilités ont été découvertes dans Apache HTTP Server. Certaines d'entre elles permettent à un attaquant de provoquer un déni de service à distance, un contournement de la politique de sécurité et une atteinte à l'intégrité des données.

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-1042Multiples vulnérabilités dans Zimbra Collaboration

De multiples vulnérabilités ont été découvertes dans Zimbra Collaboration. Certaines d'entre elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur, une exécution de code arbitraire à distance et une atteinte à la confidentialité des données.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2022-002152Apache HTTP Server の mod_proxy_ajp における HTTP リクエストスマグリングに関する脆弱性

Apache HTTP Server の mod_proxy_ajp には、HTTP リクエストスマグリングに関する脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
Action
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Applications using the APR libraries, such as httpd, must be restarted for this update to take effect. After installing the updated packages, the httpd daemon will be restarted automatically.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 8 Jun 2022 · Last source change 3 Aug 2024, 05:03 UTC · CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2022-30936
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    Apache HTTP Server 2.4 ≤ 2.4.53 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Apache HTTP Server 2.4 ≤ 2.4.53 · Fixed: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Applications using the APR libraries, such as httpd, must be restarted for this update to take effect. After installing the updated packages, the httpd daemon will be restarted automatically.
    Red Hat Product Security ↗
  2. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2022-30936↗Red Hat Product Security security advisory↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2022-26377 · cve.blacktree.nl