CVE-2026-5315
Memory Safety in Nothings Stb Truetype.H ≤ 1.26
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-5315 is a low-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Nothings Stb Truetype.H. Its CVSS base score is 2.1 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique Process Injection (T1055); ranked at the 41th 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-2026-5315 is an out-of-bounds read vulnerability affecting Nothings' stb library up to version 1.26. The issue resides in the stbtt__buf_get8 function within the stb_truetype.h file of the TTF File Handler component. It is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-125 (Out-of-bounds Read), with a CVSS v3.1 base score of 4.3 (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L).
The vulnerability enables remote exploitation without requiring attacker privileges, though it demands user interaction. An attacker can craft a malicious TTF file that, when processed by an affected application using the stb library, triggers the out-of-bounds read, potentially resulting in a low-impact denial of service such as application crashes.
Advisories from VulDB indicate that the vendor was contacted early about the disclosure but provided no response, and no patches or mitigations have been issued. An exploit has been publicly disclosed via a GitHub Gist.
The exploit's public availability increases the risk of utilization in targeted attacks against applications relying on stb for TTF parsing.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-18109
Vulnerability Data
A vulnerability was determined in Nothings stb up to 1.26. The affected element is the function stbtt__buf_get8 in the library stb_truetype.h of the component TTF File Handler. Executing a manipulation can lead to out-of-bounds read. The attack can be executed…
more
remotely. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure but did not respond in any way.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V17.3.2
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 memory-safe design and coding that structurally avoids buffer-boundary violations.
Process isolation confines the effects of an out-of-bounds read to the compromised process.
Input validation directly enforces bounds checking that stops out-of-bounds reads/writes from being introduced or reached.
Memory protection restricts exploitation impact of buffer overflows without eliminating the underlying coding flaw.
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 (bounds checking, safe APIs, reviews) directly prevent this class of flaw.
Vulnerability scanning and code analysis directly surface buffer-boundary flaws.
Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.
Developer training on secure coding reduces introduction of memory-buffer errors.
Patching replaces vulnerable code containing buffer-boundary defects.
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 catches out-of-bounds accesses before release, covering most instances of the weakness.
Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.
Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.
Application security requirements can specify memory-safety rules, but do not prescribe implementation details.
Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.
Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.