Raw vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-0861 is a high-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Gnu Glibc. Its CVSS base score is 8.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 28th 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-2026-0861 is an integer overflow vulnerability (CWE-190) in the memalign suite of functions—specifically memalign, posix_memalign, and aligned_alloc—within the GNU C Library (glibc) versions 2.30 through 2.42. Passing an excessively large alignment value alongside a size near PTRDIFF_MAX triggers the overflow, resulting in heap corruption. The vulnerable alignment inputs are constrained to narrow ranges: [1<<62 + 1, 1<<63] for memalign and exactly 1<<63 for posix_memalign and aligned_alloc.
Exploitation requires an attacker to control both the size and alignment arguments passed to these functions. With a CVSS v3.1 base score of 8.4 (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), a local attacker needs no privileges and can achieve high impacts on confidentiality, integrity, and availability, potentially enabling heap-based exploits like arbitrary code execution. However, alignments are typically fixed values (e.g., page or block sizes) not under attacker control, making direct exploitation uncommon without a separate application bug, such as another overflow propagating invalid inputs.
Advisories and patches are detailed in the glibc security advisory GLIBC-SA-2026-0001 (https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0001), the upstream Bugzilla tracker (https://sourceware.org/bugzilla/show_bug.cgi?id=33796), and oss-security mailing list discussions (http://www.openwall.com/lists/oss-security/2026/01/16/5).
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-2441
Vulnerability Data
Passing too large an alignment to the memalign suite of functions (memalign, posix_memalign, aligned_alloc) in the GNU C Library version 2.30 to 2.42 may result in an integer overflow, which could consequently result in a heap corruption. Note that the…
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attacker must have control over both, the size as well as the alignment arguments of the memalign function to be able to exploit this. The size parameter must be close enough to PTRDIFF_MAX so as to overflow size_t along with the large alignment argument. This limits the malicious inputs for the alignment for memalign to the range [1<<62+ 1, 1<<63] and exactly 1<<63 for posix_memalign and aligned_alloc. Typically the alignment argument passed to such functions is a known constrained quantity (e.g. page size, block size, struct sizes) and is not attacker controlled, because of which this may not be easily exploitable in practice. An application bug could potentially result in the input alignment being too large, e.g. due to a different buffer overflow or integer overflow in the application or its dependent libraries, but that is again an uncommon usage pattern given typical sources of alignments.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.2.6
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.
Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.
Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.
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 SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.
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 can detect integer overflows before release.
Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.
Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.
Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.
Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.