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NVD / CVE Program· CNA GitHub_M

CVE-2026-40164: jq: Algorithmic complexity DoS via hardcoded MurmurHash3 seed

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.36% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: azl3 jq 1.7.1-4 on Azure Linux 3.0 1.7.1-5; cbl2 jq 1.6-5 on CBL Mariner 2.0 1.6-6; cbl2 jq 1.6-5 on CBL-Mariner 2.0 1.6-6.

Low priority for now. Upgrade to azl3 jq 1.7.1-4 on Azure Linux 3.0 1.7.1-5; cbl2 jq 1.6-5 on CBL Mariner 2.0 1.6-6; cbl2 jq 1.6-5 on CBL-Mariner 2.0 1.6-6 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

jq is a command-line JSON processor. Before commit 0c7d133c3c7e37c00b6d46b658a02244fdd3c784, jq used MurmurHash3 with a hardcoded, publicly visible seed (0x432A9843) for all JSON object hash table operations, which allowed an attacker to precompute key collisions offline. By supplying a crafted JSON object (~100 KB) where all keys hashed to the same bucket, hash table lookups degraded from O(1) to O(n), turning any jq expression into an O(n²) operation and causing significant CPU exhaustion. This affected common jq use cases such as CI/CD pipelines, web services, and data processing scripts, and was far more practical to exploit than existing heap overflow issues since it required only a small payload. This issue has been patched in commit 0c7d133c3c7e37c00b6d46b658a02244fdd3c784.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Apr 14, 2026
Updated
Oct 26, 2026
EPSS
0.3% · 30th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
7.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-40164

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
enterprise linux10.1
enterprise linux10.2
enterprise linux eus10.0
enterprise linux8
rhel aus8.4
rhel eus long life8.4
rhel aus8.6
rhel tus8.6
rhel e4s8.6
rhel tus8.8
rhel e4s8.8
enterprise linux9

and 15 more

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • jqlang jq

    • < 0c7d133c3c7e37c00b6d46b658a02244fdd3c784affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10jqbefore 1.7.1-11.el10_2.21.7.1-11.el10_2.2
AlmaLinux:10jqbefore 1.7.1-11.el10_1.0.21.7.1-11.el10_1.0.2
AlmaLinux:10jq-develbefore 1.7.1-11.el10_2.21.7.1-11.el10_2.2
AlmaLinux:10jq-develbefore 1.7.1-11.el10_1.0.21.7.1-11.el10_1.0.2
AlmaLinux:8jqbefore 1.6-12.el8_101.6-12.el8_10
AlmaLinux:8jq-develbefore 1.6-12.el8_101.6-12.el8_10
AlmaLinux:9jqbefore 1.6-19.el9_7.0.21.6-19.el9_7.0.2
AlmaLinux:9jqbefore 1.6-19.el9_8.21.6-19.el9_8.2
AlmaLinux:9jq-develbefore 1.6-19.el9_8.21.6-19.el9_8.2
AlmaLinux:9jq-develbefore 1.6-19.el9_7.0.21.6-19.el9_7.0.2
Alpine:v3.22jqbefore 1.8.2-r01.8.2-r0
Debian:12jqbefore 1.6-2.1+deb12u21.6-2.1+deb12u2
Debian:13jqbefore 1.7.1-6+deb13u21.7.1-6+deb13u2
Debian:14jqbefore 1.8.1-51.8.1-5
openSUSE:Leap 16.0jqbefore 1.7.1-160000.3.11.7.1-160000.3.1
openSUSE:Tumbleweedjqbefore 1.8.1-3.11.8.1-3.1
Red Hat:enterprise_linux_eus:10.0jqbefore 0:1.7.1-8.el10_0.30:1.7.1-8.el10_0.3
Red Hat:enterprise_linux_eus:10.0jq-debuginfobefore 0:1.7.1-8.el10_0.30:1.7.1-8.el10_0.3
Red Hat:enterprise_linux_eus:10.0jq-debugsourcebefore 0:1.7.1-8.el10_0.30:1.7.1-8.el10_0.3
Red Hat:enterprise_linux_eus:10.0jq-develbefore 0:1.7.1-8.el10_0.30:1.7.1-8.el10_0.3
Red Hat:enterprise_linux:10.1jqbefore 0:1.7.1-11.el10_1.0.20:1.7.1-11.el10_1.0.2
Red Hat:enterprise_linux:10.1jq-debuginfobefore 0:1.7.1-11.el10_1.0.20:1.7.1-11.el10_1.0.2
Red Hat:enterprise_linux:10.1jq-debugsourcebefore 0:1.7.1-11.el10_1.0.20:1.7.1-11.el10_1.0.2
Red Hat:enterprise_linux:10.1jq-develbefore 0:1.7.1-11.el10_1.0.20:1.7.1-11.el10_1.0.2

+52

Same product

jqlang: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-53427decNumberCopy in decNumber.c in jq through 1.7.1 does not properly consider that NaN is interpreted as numeric, which has a resultant stack-
    32Monitor
  • CVE-2026-32316jq: Integer overflow in jvp_string_append() allows Heap-based Buffer Overflow
    30Monitor
  • CVE-2025-48060AddressSanitizer: stack-buffer-overflow in jq_fuzz_execute (jv_string_vfmt)
    30Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-39979Apr 13, 2026 · jq: Out-of-Bounds Read in jv_parse_sized() Error Formatting for Non-NUL-Terminated Counted Buffers
    27Monitor
  • ← EarlierCVE-2026-33948Apr 14, 2026 · jq: Embedded-NUL Truncation in CLI JSON Input Path Causes Prefix-Only Validation of Malformed Input
    11Monitor
  • Later →CVE-2026-40612May 11, 2026 · jq: Stack overflow via unbounded recursion in jv_contains
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
azl3 jq 1.7.1-4 on Azure Linux 3.01.7.1-5 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 jq 1.6-5 on CBL Mariner 2.01.6-6 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 jq 1.6-5 on CBL-Mariner 2.01.6-6 · Release NotesMicrosoft (MSRC)
almalinux:jq1.6-12.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:jq-devel1.6-12.el8_10 · AlmaLinux:8Package registry (OSV)
alpine:jq1.8.2-r0 · Alpine:v3.22Package registry (OSV)
debian:jq1.6-2.1+deb12u2 · Debian:12Package registry (OSV)
opensuse:jq1.8.1-3.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:jq0:1.6-12.el8_10 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:jq-debuginfo0:1.6-12.el8_10 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:jq-debugsource0:1.6-12.el8_10 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:jq-devel0:1.6-12.el8_10 · Red Hat:enterprise_linux:8::crbPackage registry (OSV)
rocky linux:jq0:1.6-12.el8_10 · Rocky Linux:8Package registry (OSV)
suse:jq1.7.1-160000.3.1 · SUSE:Linux Micro 6.2Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-328 · Use of Weak Hash

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (19 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records