Application crashes via embedded-null key emission
Published Mar 17, 2026 · Updated Mar 17, 2026
Out-of-bounds read in libucl commit 3e7f023e184e06f30fb5792dacd9dd0f8b692f1b allows remote attackers to crash applications via crafted UCL input. In UCL_PARSER_ZEROCOPY mode, ucl_elt_string_write_json treats an embedded-null key as a valid null-terminated C string and reads invalid memory during ucl_object_emit. The crash requires an application to parse attacker-controlled UCL in zero-copy mode and then emit the resulting object.
Summary
What happened
Out-of-bounds read in libucl commit 3e7f023e184e06f30fb5792dacd9dd0f8b692f1b allows remote attackers to crash applications via crafted UCL input. In UCL_PARSER_ZEROCOPY mode, ucl_elt_string_write_json treats an embedded-null key as a valid null-terminated C string and reads invalid memory during ucl_object_emit. The crash requires an application to parse attacker-controlled UCL in zero-copy mode and then emit the resulting object.
The record
- CVE
- CVE-2026-0708
- Published
- Mar 17, 2026
- Updated
- Mar 17, 2026
- Vendor
- Vsevolod Stakhov
- Product
- libucl
- Classifications
- CWE-125, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 17, 2026CVE publishedPublication date reported by the CVE source.
- Mar 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3e7f023e184e06f30fb5792dacd9dd0f8b692f1b
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Upstream embedded-null UCL reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo