jq is a command-line JSON processor. In 1.8.1 and earlier, unbounded recursion in jv_object_merge_recursive() allows a crafted jq program to crash the process with a segfault. The function is reachable through the * operator when both operands are objects.

An update of the jq package has been released.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-1815 advisory.

    jq is a command-line JSON processor. An integer overflow vulnerability exists through version 1.8.1 within     the jvp_string_append() and jvp_string_copy_replace_bad functions, where concatenating strings with a     combined length exceeding 2^31 bytes causes a 32-bit unsigned integer overflow in the buffer allocation     size calculation, resulting in a drastically undersized heap buffer. Subsequent memory copy operations     then write the full string data into this undersized buffer, causing a heap buffer overflow classified as     CWE-190 (Integer Overflow) leading to CWE-122 (Heap-based Buffer Overflow). Any system evaluating     untrusted jq queries is affected, as an attacker can crash the process or potentially achieve further     exploitation through heap corruption by crafting queries that produce extremely large strings. The root     cause is the absence of string size bounds checking, unlike arrays and objects which already have size     limits. The issue has been addressed in commit e47e56d226519635768e6aab2f38f0ab037c09e5. (CVE-2026-32316)

    jq is a command-line JSON processor. In versions 1.8.1 and below, functions jv_setpath(), jv_getpath(),     and delpaths_sorted() in jq's src/jv_aux.c use unbounded recursion whose depth is controlled by the length     of a caller-supplied path array, with no depth limit enforced. An attacker can supply a JSON document     containing a flat array of ~65,000 integers (~200 KB) that, when used as a path argument by a trusted jq     filter, exhausts the C call stack and crashes the process with a segmentation fault (SIGSEGV). This bypass     works because the existing MAX_PARSING_DEPTH (10,000) limit only protects the JSON parser, not runtime     path operations where arrays can be programmatically constructed to arbitrary lengths. The impact is     denial of service (unrecoverable crash) affecting any application or service that processes untrusted JSON     input through jq's setpath, getpath, or delpaths builtins. This issue has been addressed in commit     fb59f1491058d58bdc3e8dd28f1773d1ac690a1f. (CVE-2026-33947)

    jq is a command-line JSON processor. Commits before 6374ae0bcdfe33a18eb0ae6db28493b1f34a0a5b contain a     vulnerability where CLI input parsing allows validation bypass via embedded NUL bytes. When reading JSON     from files or stdin, jq uses strlen() to determine buffer length instead of the actual byte count from     fgets(), causing it to truncate input at the first NUL byte and parse only the preceding prefix. This     enables an attacker to craft input with a benign JSON prefix before a NUL byte followed by malicious     trailing data, where jq validates only the prefix as valid JSON while silently discarding the suffix.
    Workflows relying on jq to validate untrusted JSON before forwarding it to downstream consumers are     susceptible to parser differential attacks, as those consumers may process the full input including the     malicious trailing bytes. This issue has been patched by commit 6374ae0bcdfe33a18eb0ae6db28493b1f34a0a5b.
    (CVE-2026-33948)

    jq is a command-line JSON processor. In commits after 69785bf77f86e2ea1b4a20ca86775916889e91c9, the
    _strindices builtin in jq's src/builtin.c passes its arguments directly to jv_string_indexes() without     verifying they are strings, and jv_string_indexes() in src/jv.c relies solely on assert() checks that are     stripped in release builds compiled with -DNDEBUG. This allows an attacker to crash jq trivially with     input like _strindices(0), and by crafting a numeric value whose IEEE-754 bit pattern maps to a chosen     pointer, achieve a controlled pointer dereference and limited memory read/probe primitive. Any deployment     that evaluates untrusted jq filters against a release build is vulnerable. This issue has been patched in     commit fdf8ef0f0810e3d365cdd5160de43db46f57ed03. (CVE-2026-39956)

    jq is a command-line JSON processor. In commits before 2f09060afab23fe9390cce7cb860b10416e1bf5f, the     jv_parse_sized() API in libjq accepts a counted buffer with an explicit length parameter, but its error-     handling path formats the input buffer using %s in jv_string_fmt(), which reads until a NUL terminator is     found rather than respecting the caller-supplied length. This means that when malformed JSON is passed in     a non-NUL-terminated buffer, the error construction logic performs an out-of-bounds read past the end of     the buffer. The vulnerability is reachable by any libjq consumer calling jv_parse_sized() with untrusted     input, and depending on memory layout, can result in memory disclosure or process termination. The issue     has been patched in commit 2f09060afab23fe9390cce7cb860b10416e1bf5f. (CVE-2026-39979)

    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. (CVE-2026-40164)

    jq is a command-line JSON processor. In 1.8.1 and earlier, when decNumberFromString is given a number     literal of INT_MAX-1 (2147483646) digits, the D2U() macro overflows during signed-int arithmetic. The     wrapped negative value bypasses the heap-allocation size check, causes the function to use a 30-byte stack     buffer, and then writes [?]715 million 16-bit units ([?]1.4 GiB) at an offset 1.43 GiB below the stack     frame. The written content is fully attacker-controlled (the parsed decimal digits, packed 3-per-unit).
    (CVE-2026-43894)

    jq is a command-line JSON processor. In 1.8.1 and earlier, unbounded recursion in     jv_object_merge_recursive() allows a crafted jq program to crash the process with a segfault. The function     is reachable through the * operator when both operands are objects. (CVE-2026-43896)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4599 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-4599-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                  Andreans Henriksson     May 25, 2026                                  https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : jq     Version        : 1.6-2.1+deb11u2     CVE ID         : CVE-2026-32316 CVE-2026-33947 CVE-2026-33948 CVE-2026-39956                      CVE-2026-39979 CVE-2026-40164 CVE-2026-41256 CVE-2026-41257                      CVE-2026-43895 CVE-2026-43896 CVE-2026-44777     Debian Bug     : 1136445

    It was found that jq, a lightweight and flexible command-line JSON parser, was     vulnerable to multiple memory corruption attacks, which could lead to     application crashes, denial-of-service conditions, and potentially arbitrary     code execution through heap corruption when parsing untrusted input.

    For Debian 11 bullseye, these problems have been fixed in version     1.6-2.1+deb11u2.

    We recommend that you upgrade your jq packages.

    For the detailed security status of jq please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/jq

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS     Attachment:
    signature.asc     Description: PGP signature

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - jq is a command-line JSON processor. In 1.8.1 and earlier, unbounded recursion in     jv_object_merge_recursive() allows a crafted jq program to crash the process with a segfault. The function     is reachable through the * operator when both operands are objects. (CVE-2026-43896)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
321792	Photon OS 5.0: Jq PHSA-2026-5.0-0885	Nessus	PhotonOS Local Security Checks	high
319811	Amazon Linux 2023 : jq, jq-devel (ALAS2023-2026-1815)	Nessus	Amazon Linux Local Security Checks	medium
316545	Debian dla-4599 : jq - security update	Nessus	Debian Local Security Checks	high
314260	Linux Distros Unpatched Vulnerability : CVE-2026-43896	Nessus	Misc.	medium

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CVE-2026-43896

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medium