CVE-2026-40612: jq: Stack overflow via unbounded recursion in jv_contains
Vulnerability summary
CVE-2026-40612 is a medium (CVSS 5.5) Uncontrolled Recursion vulnerability in jqlang jq. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 5.3% of scored vulnerabilities. 1 public exploit is recorded.
Not severe (CVSS 5.4, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 8 · Related 7Timeline
- 11-05-2026PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
jq is a command-line JSON processor. In 1.8.1 and earlier, jv_contains recurses into nested arrays/objects with no depth limit. With a sufficiently nested input structure (built programmatically with reduce, since the JSON parser caps at depth 10000), the C stack is exhausted.
CVSS metrics
7 scores · 5 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated6.8MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:PDiffers
- NVDNIST5.4MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/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
- OSV · AlpineEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.16%
Chance of exploitation in the next 30 days
Percentile
5%
Versus all other CVEs
30-day change
Increase +0.01 pp
From 0.16% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundJq
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.
Alpine1 product
- jq< 1.8.2-r0
Debian1 product
- jqAll versions (No fix recorded) | < 1.7.1-6+deb13u3 | < 1.8.1-6
Jqlang1 product
- jq≤ 1.8.1
Ubuntu1 product
- jqAll versions (No fix recorded)
4 vendors · 4 products
References
6 links- github.com/jqlang/jq/security/advisories/GHSA-r7m6-x9c7-h69jX Refsource CONFIRMREPORTExploitMitigationVendor Advisory
