CVE-2026-5673
Memory Safety in Redhat Enterprise Linux 10.0 … 9.0
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-5673 is a medium-severity Out-of-bounds Read (CWE-125) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 5.6 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-5673 is a heap-based out-of-bounds read vulnerability (CWE-125) in the libtheora library, specifically within the AVI parser's avi_parse_input_file() function. The issue arises when processing a specially crafted AVI file with a truncated header sub-chunk, affecting applications that use libtheora for Theora video decoding.
A local attacker with low privileges can exploit this vulnerability by tricking a user into opening a malicious AVI file. This requires low attack complexity and user interaction but no elevated privileges or scope changes. Exploitation leads to a denial-of-service (application crash, high availability impact) or potential leakage of sensitive heap information (low confidentiality impact), as scored at CVSS 5.6 (CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:H).
Advisories and patches for mitigation are detailed in the Red Hat security bulletin at https://access.redhat.com/security/cve/CVE-2026-5673, the associated Bugzilla entry at https://bugzilla.redhat.com/show_bug.cgi?id=2455340, and the upstream GitHub issue at https://github.com/xiph/theora/issues/24.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19219
Vulnerability Data
A flaw was found in libtheora. This heap-based out-of-bounds read vulnerability exists within the AVI (Audio Video Interleave) parser, specifically in the avi_parse_input_file() function. A local attacker could exploit this by tricking a user into opening a specially crafted AVI…
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file containing a truncated header sub-chunk. This could lead to a denial-of-service (application crash) or potentially leak sensitive information from the heap.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.
Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.
Process isolation confines the effects of an out-of-bounds read to the compromised process.
Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.
Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.
Routine patching replaces vulnerable code containing out-of-bounds read flaws.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.
Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.
Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.
Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.
Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.
Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.