Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 0.31% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-44235High confidence
rabbitmq-c: size_t underflow in AMQP frame length computation leads to out-of-bounds read
alanxz · rabbitmq-c
Official source article: GitHub GHSA-9MMV-R8G3-QP46 ↗. Check the applicable product and release in the original source.
6.5MediumCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productMedium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 14 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:High, raised one band.upgradedsince 17 Sep 2026
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs alanxz rabbitmq-c and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 14 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Red Hat Product Security: 14 affected or under-investigation product states without a fixed product state in the same current advisory
Distribution package intelligence
5 package statesRelease-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
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 release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | librabbitmq | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.15.0-1+deb13u1 | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian bookwormbookworm · source | librabbitmq | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.11.0-1+deb12u2 | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian forkyforky · source | librabbitmq | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.16.0-1 | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian sidsid · source | librabbitmq | Vendor fix publishedDebian records a fixed source-package version for this release. | 0.16.0-1 | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | librabbitmq | Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree. | 0.11.0-1ubuntu0.1 | Canonical Ubuntu Security ↗Source updated 7 Oct 2026 |
Direct vendor intelligence
1 currentAuthoritative 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.
CVE-2026-44235 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityrabbitmq-c: github.com/alanxz/rabbitmq-c: rabbitmq-c: Denial of Service via AMQP frame length underflow
The vendor explicitly identifies these products as affected by this CVE.
- librabbitmq-devel as a component of Red Hat Enterprise Linux 10
- librabbitmq-tools as a component of Red Hat Enterprise Linux 10
- librabbitmq.src as a component of Red Hat Enterprise Linux 10
- librabbitmq as a component of Red Hat Enterprise Linux 7
- librabbitmq-devel as a component of Red Hat Enterprise Linux 7
- librabbitmq-examples as a component of Red Hat Enterprise Linux 7
- librabbitmq.src as a component of Red Hat Enterprise Linux 7
- librabbitmq as a component of Red Hat Enterprise Linux 8
- librabbitmq-devel as a component of Red Hat Enterprise Linux 8
- librabbitmq.src as a component of Red Hat Enterprise Linux 8
- librabbitmq as a component of Red Hat Enterprise Linux 9
- librabbitmq-devel as a component of Red Hat Enterprise Linux 9
- Summary
- A flaw was found in rabbitmq-c, a C-language AMQP (Advanced Message Queuing Protocol) client library. A malicious AMQP server or an on-path attacker can send an undersized HEADER or METHOD frame during client login, leading to an unsigned size_t underflow. This underflow causes an out-of-bounds read, which can result in a process crash and a denial of service (DoS).
- Remediation
- To mitigate this issue, ensure that all AMQP client connections are configured to use TLS with certificate validation. This prevents on-path attackers from exploiting the vulnerability by ensuring the authenticity of the AMQP server and encrypting traffic. Proper certificate management and configuration are required on both the client and server sides. Restart any services utilizing `rabbitmq-c` after applying this configuration change for it to take effect.
Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 14 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
rabbitmq-c is a C-language AMQP client library for RabbitMQ. Prior to 0.16.0, a malicious AMQP server can send an undersized HEADER or METHOD frame during client login and cause unsigned size_t underflow in amqp_handle_input() in librabbitmq/amqp_connection.c. The parser subtracts HEADER_SIZE, fixed per-frame fields, and FOOTER_SIZE from state->target_size without first checking the minimum frame length. The wrapped encoded.len value is passed through amqp_decode_properties() to amqp_decode_table_internal(), where it defeats bounds checks and causes an out-of-bounds read and process crash. An on-path attacker can also trigger the issue when AMQP traffic is not protected by TLS with certificate validation. The demonstrated impact is denial of service, with no reliable memory disclosure or code execution shown. This issue is fixed in version 0.16.0.
What
rabbitmq-c is a C-language AMQP client library for RabbitMQ. Prior to 0.16.0, a malicious AMQP server can send an undersized HEADER or METHOD frame during client login and cause unsigned size_t underflow in amqp_handle_input() in librabbitmq/amqp_connection.c. The parser subtracts HEADER_SIZE, fixed per-frame fields, and FOOTER_SIZE from state->target_size without first checking the minimum frame length. The wrapped encoded.len value is passed through amqp_decode_properties() to amqp_decode_table_internal(), where it defeats bounds checks and causes an out-of-bounds read and process crash. An on-path attacker can also trigger the issue when AMQP traffic is not protected by TLS with certificate validation. The demonstrated impact is denial of service, with no reliable memory disclosure or code execution shown. This issue is fixed in version 0.16.0.
Why
The product reads data past the end, or before the beginning, of the intended buffer.
How
An attacker operating through a network path may attempt exploitation without authentication after a user interaction. If successful, the issue may disrupt the affected service.
What
rabbitmq-c is a C-language AMQP client library for RabbitMQ. Prior to 0.16.0, a malicious AMQP server can send an undersized HEADER or METHOD frame during client login and cause unsigned size_t underflow in amqp_handle_input() in librabbitmq/amqp_connection.c. The parser subtracts HEADER_SIZE, fixed per-frame fields, and FOOTER_SIZE from state->target_size without first checking the minimum frame length. The wrapped encoded.len value is passed through amqp_decode_properties() to amqp_decode_table_internal(), where it defeats bounds checks and causes an out-of-bounds read and process crash. An on-path attacker can also trigger the issue when AMQP traffic is not protected by TLS with certificate validation. The demonstrated impact is denial of service, with no reliable memory disclosure or code execution shown. This issue is fixed in version 0.16.0.
Why
The product reads data past the end, or before the beginning, of the intended buffer.
How
An attacker operating through a network path may attempt exploitation without authentication after a user interaction. If successful, the issue may disrupt the affected service.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.
- Likely attack path
- a network path → Out-of-bounds Read → disrupt the affected service
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- Required interaction required
- 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-125 ↗
CWE-125: Out-of-bounds Read. The product reads data past the end, or before the beginning, of the intended buffer.
- 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:R/S:U/C:N/I:N/A:HCommon 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.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.- 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.
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. - Fix availability varies by product
- Affected
- librabbitmq-devel as a component of Red Hat Enterprise Linux 10
- librabbitmq-tools as a component of Red Hat Enterprise Linux 10
- librabbitmq.src as a component of Red Hat Enterprise Linux 10
- librabbitmq as a component of Red Hat Enterprise Linux 7
- librabbitmq-devel as a component of Red Hat Enterprise Linux 7
- librabbitmq-examples as a component of Red Hat Enterprise Linux 7
- librabbitmq.src as a component of Red Hat Enterprise Linux 7
- librabbitmq as a component of Red Hat Enterprise Linux 8
- librabbitmq-devel as a component of Red Hat Enterprise Linux 8
- librabbitmq.src as a component of Red Hat Enterprise Linux 8
- librabbitmq as a component of Red Hat Enterprise Linux 9
- librabbitmq-devel as a component of Red Hat Enterprise Linux 9
- librabbitmq-tools as a component of Red Hat Enterprise Linux 9
- librabbitmq.src as a component of Red Hat Enterprise Linux 9
- Fixed
- 0.16.0.
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- Workaround
- To mitigate this issue, ensure that all AMQP client connections are configured to use TLS with certificate validation. This prevents on-path attackers from exploiting the vulnerability by ensuring the authenticity of the AMQP server and encrypting traffic. Proper certificate management and configuration are required on both the client and server sides. Restart any services utilizing `rabbitmq-c` after applying this configuration change for it to take effect.
04
Evidence and provenance
Published 17 Sept 2026 · Last source change 17 Sept 2026, 17:43 UTC · CWE-125 · Out-of-bounds Read
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-09-18
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-82333
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-82333 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-82333"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
- Vendor guidanceAuthoritative vendor guidance changed: added remediation: github.com/GHSA-9mmv-r8g3-qp46; removed remediation: github.com/1d3afbb056fee5cc9ea05680bf32288715d0d802.CNA ↗
- Before
- remediation: github.com/1d3afbb056fee5cc9ea05680bf32288715d0d802
- After
- remediation: github.com/GHSA-9mmv-r8g3-qp46
CVE published
Fixed release or patch reference recorded
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.