Cyber Resilience

CVE-2026-5314

Memory Safety in Nothings Stb Truetype.H ≤ 1.26

Public PoCMemory Safety
Published
01 April 2026
Modified
30 April 2026
CVSS Score v4 2.1
Click a component to see what it means
Raw vectorCVSS: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:X
EPSS Score 0.0066 49th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2026-5314 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 49th 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-2026-5314 is an out-of-bounds read vulnerability affecting Nothings stb single-header library versions up to 1.26. The issue resides in the stbtt_InitFont_internal function within the stb_truetype.h library, part of the TTF File Handler component. Manipulation of a TTF file triggers the out-of-bounds read, as documented with CWEs-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-125 (Out-of-bounds Read).

Remote attackers can exploit this vulnerability over the network (AV:N) with low attack complexity (AC:L), requiring no privileges (PR:N) but user interaction (UI:R), unchanged scope (S:U), no confidentiality or integrity impact (C:N/I:N), and low availability impact (A:L), yielding a CVSS v3.1 base score of 4.3. Exploitation causes a denial-of-service condition through memory corruption, and a public exploit is available for potential use by unauthenticated attackers.

Advisories and details are provided in references including a GitHub gist at https://gist.github.com/d0razi/cb31a92f3205a4373f19b7da25946848 containing the exploit, along with VulDB entries at https://vuldb.com/submit/780558, https://vuldb.com/vuln/354646, and https://vuldb.com/vuln/354646/cti. The vendor was contacted early for disclosure but provided no response, with no patches or official mitigations noted.

The exploit has been publicly disclosed and could be used, published on 2026-04-01.

EU & UK References

Vulnerability Data

A vulnerability was found in Nothings stb up to 1.26. Impacted is the function stbtt_InitFont_internal in the library stb_truetype.h of the component TTF File Handler. Performing a manipulation results in out-of-bounds read. Remote exploitation of the attack is possible. The…

more

exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not respond in any way.

CWE(s)
CWE-119CWE-125

Related Threats

MITRE ATT&CK Enterprise Techniques

T1055 Process Injection Stealth
Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges.
attack.mitre.org →
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-5315Same product: Nothings Stb Truetype.H
CVE-2025-3406Same vendor: Nothings
CVE-2025-3407Same vendor: Nothings
CVE-2023-45661Same vendor: Nothings
CVE-2023-45682Same vendor: Nothings
CVE-2023-45662Same vendor: Nothings
CVE-2026-5317Same vendor: Nothings
CVE-2025-3409Same vendor: Nothings
CVE-2025-6271Shared CWE-119, CWE-125
CVE-2025-5203Shared CWE-119, CWE-125

Affected Assets

nothings
stb truetype.h
≤ 1.26

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V17.3.2

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles require memory-safe design and coding that structurally avoids buffer-boundary violations.

SC-39 Process Isolation partial match

Process isolation confines the effects of an out-of-bounds read to the compromised process.

SI-10 Information Input Validation partial match

Input validation directly enforces bounds checking that stops out-of-bounds reads/writes from being introduced or reached.

SI-16 Memory Protection partial match

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices (bounds checking, safe APIs, reviews) directly prevent this class of flaw.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis directly surface buffer-boundary flaws.

ID.RA-08 partial match
prevents

Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.

PR.AT-02 partial match
prevents

Developer training on secure coding reduces introduction of memory-buffer errors.

PR.PS-02 partial match
prevents

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.

A.8.15 Logging partial match
finds

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

References