Bug 2458085 (CVE-2026-33948)

Summary:	CVE-2026-33948 jq: jq: Input validation bypass via embedded NUL bytes allows parser differential attacks
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	akhatavk, amctagga, aoconnor, aos-team-art-private, asdas, bniver, dpaolell, flucifre, gmeno, groman, jdelft, jupierce, lgarciaa, mbenjamin, mbiarnes, mhackett, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, sostapov, suppawar, vereddy, vlaad, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in jq, a command-line JSON processor. This vulnerability allows a remote attacker to bypass input validation by crafting malicious JSON input containing embedded null (NUL) bytes. Due to incorrect handling of input buffer lengths, jq truncates the input at the first NUL byte, validating only the benign prefix and silently discarding any malicious data that follows. This can lead to parser differential attacks where downstream systems, relying on jq for validation, may process the full, unvalidated input, potentially leading to unexpected behavior or security compromises.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2458354
Bug Blocks:

Description OSIDB Bzimport 2026-04-14 00:01:31 UTC

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.