TI-2026-09004 Aliases CVE-2026-10268 GHSA-gqw4-cq8m-g989

janet-lang janet marsh.c unmarshal_one_fiber integer overflow

MEDIUM 55CWE-189Published 2026-06-01 · Updated 2026-06-01

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: —
Confidentiality · integrity · availability: None · None · Low
Fix status: No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00121 1st percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by the CNA

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
janet-lang	janet	1.0; 1.1; 1.2; 1.3; 1.4; 1.5; 1.6; 1.7; 1.8; 1.9; 1.10; 1.11; 1.12; 1.13; 1.14; 1.15; 1.16; 1.17; 1.18; 1.19; 1.20; 1.21; 1.22; 1.23; 1.24; 1.25; 1.26; 1.27; 1.28; 1.29; 1.30; 1.31; 1.32; 1.33; 1.34; 1.35; 1.36; 1.37; 1.38; 1.39; 1.40; 1.41.0	—	No fix listed	CNA

janet Vendorjanet-lang Affected 1.0; 1.1; 1.2; 1.3; 1.4; 1.5; 1.6; 1.7; 1.8; 1.9; 1.10; 1.11; 1.12; 1.13; 1.14; 1.15; 1.16; 1.17; 1.18; 1.19; 1.20; 1.21; 1.22; 1.23; 1.24; 1.25; 1.26; 1.27; 1.28; 1.29; 1.30; 1.31; 1.32; 1.33; 1.34; 1.35; 1.36; 1.37; 1.38; 1.39; 1.40; 1.41.0 Fixed in — No fix listed CNA

CPE names CNA · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:janet-lang:janet::::::::	—	—	janet-lang

cpe:2.3:a:janet-lang:janet:*:*:*:*:*:*:*:* Versions — — ·janet-lang

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-02 Threatist record created from CVE-2026-10268
2026-10-03 Alias added: GHSA-gqw4-cq8m-g989

References

Exploit 1

https://github.com/biniamf/pocs/tree/main/janet-marsh-unmarshal-intovf

Patch 1

https://github.com/janet-lang/janet/commit/d9b1d711ea1fde52ac73a82088b512a3e17bad0d

Other 2

TI-2026-09003 janet-lang janet debug.c doframe out-of-bounds CVSS 4.0MEDIUM 4.8
TI-2026-02464 janet-lang janet handleattr specials.c janetc_varset out-of-bounds CVSS 4.0MEDIUM 4.8
TI-2026-01889 janet-lang janet specials.c janetc_if out-of-bounds CVSS 4.0MEDIUM 4.8
TI-2026-01887 janet-lang janet compile.c janetc_pop_funcdef out-of-bounds CVSS 4.0MEDIUM 4.8
TI-2022-12896 Janet before 1.22.0 mishandles arrays. CVSS 3.1HIGH 7.5
TI-2026-01888 janet-lang janet os.c os_strftime out-of-bounds CVSS 4.0MEDIUM 4.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences