BlackTreeCVE Intelligencersyslog · rsyslog
Official source article: GitHub GHSA-947W-69PH-MC2R ↗. Check the applicable product and release in the original source.
High 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 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 2 affected package states shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.
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 | rsyslog | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian bookwormbookworm · source | rsyslog | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian forkyforky · source | rsyslog | Vendor fix publishedDebian records a fixed source-package version for this release. | 8.2604.0-1 | Debian Security Tracker ↗Source updated 8 Oct 2026 |
| Debian sidsid · source | rsyslog | Vendor fix publishedDebian records a fixed source-package version for this release. | 8.2604.0-1 | Debian Security Tracker ↗Source updated 8 Oct 2026 |
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
The vendor explicitly states that these products are not affected by this CVE.
High 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 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by productRsyslog is a rocket-fast system for log processing. From 8.2110.0 until 8.2604.0, the optional imhttp module's parse_auth_header function in contrib/imhttp/imhttp.c allocates a zero-byte heap buffer with calloc(0, len) when an HTTP Basic Authorization value exceeds its fixed work buffer, then passes that pointer to apr_base64_decode. An unauthenticated remote attacker can send an oversized encoded credential to an imhttp endpoint configured for Basic Authentication, causing decoded data to overwrite adjacent heap memory before credential validation. Deployments that do not install, load, and use imhttp with Basic Authentication are not affected. The demonstrated impact is a process crash that interrupts log collection, and code execution has not been demonstrated. This issue is fixed in version 8.2604.0.
Rsyslog is a rocket-fast system for log processing. From 8.2110.0 until 8.2604.0, the optional imhttp module's parse_auth_header function in contrib/imhttp/imhttp.c allocates a zero-byte heap buffer with calloc(0, len) when an HTTP Basic Authorization value exceeds its fixed work buffer, then passes that pointer to apr_base64_decode. An unauthenticated remote attacker can send an oversized encoded credential to an imhttp endpoint configured for Basic Authentication, causing decoded data to overwrite adjacent heap memory before credential validation. Deployments that do not install, load, and use imhttp with Basic Authentication are not affected. The demonstrated impact is a process crash that interrupts log collection, and code execution has not been demonstrated. This issue is fixed in version 8.2604.0.
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
Rsyslog is a rocket-fast system for log processing. From 8.2110.0 until 8.2604.0, the optional imhttp module's parse_auth_header function in contrib/imhttp/imhttp.c allocates a zero-byte heap buffer with calloc(0, len) when an HTTP Basic Authorization value exceeds its fixed work buffer, then passes that pointer to apr_base64_decode. An unauthenticated remote attacker can send an oversized encoded credential to an imhttp endpoint configured for Basic Authentication, causing decoded data to overwrite adjacent heap memory before credential validation. Deployments that do not install, load, and use imhttp with Basic Authentication are not affected. The demonstrated impact is a process crash that interrupts log collection, and code execution has not been demonstrated. This issue is fixed in version 8.2604.0.
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.
CWE-122: Heap-based Buffer Overflow. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 18 Sept 2026 · Last source change 22 Sept 2026, 15:04 UTC · CWE-122 · Heap-based Buffer Overflow
Core structured fields are present and their contributing authorities are shown above.