EUVD-2026-33681
GHSA-gqw4-cq8m-g989
Severity by source
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/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
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/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
Lifecycle Timeline
3DescriptionCVE.org
A weakness has been identified in janet-lang janet up to 1.41.0. This vulnerability affects the function unmarshal_one_fiber of the file src/core/marsh.c. Executing a manipulation can lead to integer overflow. It is possible to launch the attack on the local host. The exploit has been made available to the public and could be used for attacks. This patch is called d9b1d711ea1fde52ac73a82088b512a3e17bad0d. A patch should be applied to remediate this issue.
AnalysisAI
Integer overflow in the Janet scripting language's fiber unmarshaling routine (versions up to 1.41.0) allows a local authenticated attacker to cause a denial-of-service condition. The vulnerable function unmarshal_one_fiber in src/core/marsh.c performs an unchecked addition when computing fiber stack capacity - if fiber_stacktop is near INT32_MAX, adding 10 wraps the value, resulting in a dangerously small capacity allocation that crashes the interpreter. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | The attacker must have local access to the host and a low-privileged account (confirmed by CVSS PR:L). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 base score of 3.3 (Low) is consistent with the attack surface: AV:L (local host only), AC:L (no special conditions), PR:L (requires a low-privileged local account), UI:N, with impact confined to availability (A:L) and no confidentiality or integrity exposure. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | A local attacker with a low-privileged account on a system running Janet crafts a malicious serialized fiber payload in which the `fiber_stacktop` field is set to a value near INT32_MAX. When the Janet interpreter calls `unmarshal_one_fiber` to deserialize this data, the unchecked addition overflows, assigning an invalid (very small) capacity to the fiber's stack buffer. … |
| Remediation | Apply upstream patch commit d9b1d711ea1fde52ac73a82088b512a3e17bad0d from the Janet GitHub repository (https://github.com/janet-lang/janet/commit/d9b1d711ea1fde52ac73a82088b512a3e17bad0d). … Detailed patch versions, workarounds, and compensating controls in full report. |
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