Cyber Resilience

CVE-2026-41257

Memory Safety in Jqlang Jq ≤ 1.8.1

Public PoCMemory Safety
Published
11 May 2026
Modified
17 June 2026
Patch / advisory
CVSS Score v4 6.4
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/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 0.0014 4th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-41257 is a medium-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Jqlang Jq. Its CVSS base score is 6.4 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 4th 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 SI-2 (Flaw Remediation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

jq is a command-line JSON processor. In 1.8.1 and earlier, the jq bytecode VM's data stack tracks its allocation size in a signed int. When the stack grows beyond ≈1 GiB (via deeply nested generator forks), the doubling arithmetic overflows.…

more

The wrapped value is passed to realloc and then used for a memmove with attacker-influenced offsets.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Why these techniques?

Integer overflow (CWE-190) leading to out-of-bounds write via realloc/memmove enables arbitrary code execution when attacker-controlled JSON input is processed by jq.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-43894Same product: Jqlang Jq
CVE-2026-54679Same product: Jqlang Jq
CVE-2026-32316Same product: Jqlang Jq
CVE-2023-49355Same product: Jqlang Jq
CVE-2024-23337Same product: Jqlang Jq
CVE-2023-50268Same product: Jqlang Jq
CVE-2023-50246Same product: Jqlang Jq
CVE-2026-0148Shared CWE-190, CWE-787
CVE-2026-7838Shared CWE-190, CWE-787
CVE-2024-32039Shared CWE-190, CWE-787

Affected Assets

jqlang
jq
≤ 1.8.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-2 Flaw Remediation
  • SI-10 Information Input Validation
  • SI-16 Memory Protection
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.2.6

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires applying patches that correct the signed-integer overflow in jq's stack-size arithmetic before realloc/memmove.

prevent

Input validation on JSON depth or generator nesting can block the oversized stack growth that triggers the wrap.

prevent

Memory-protection mechanisms (e.g., ASLR, guard pages, or bounds-checked allocators) reduce the chance that the subsequent out-of-bounds memmove succeeds.

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 directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.

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.

detects

Security testing in development can detect integer overflows before release.

prevents

Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.

degrades

Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.

degrades

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

prevents

Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.

prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

References