Buffer overflow in Esa Asn1scc
CVE-2026-76077
ASN1SCC is an open source ASN.1 compiler for embedded systems. Prior to 4.7.0.1, the XER tokenizer NT() in asn1crt/asn1crt_encoding_xer.c, which is reached by all XER decode paths, copies tag characters into a fixed char Value[100] field without a length bound and reads input and lookahead bytes without checking the buffer count. A crafted XER message with an overlong tag can overwrite the tokenizer's stack frame, while a truncated tag or unterminated processing-instruction or comment sequence can read beyond the input and may cause a CPU spin. The flaws can disclose adjacent memory, corrupt stack data, crash or hang the decoder, and potentially permit code execution. This issue is fixed in version 4.7.0.1.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Esa Asn1scc — versions < 4.7.0.1
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-76077?
- CVE-2026-76077 is a high-severity vulnerability in Esa Asn1scc, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 8.1/10. Published 2026-11-05.
- How severe is CVE-2026-76077?
- High severity. CVSS v3 base score is 8.1 out of 10.