CVE-2026-76077

CVSS 8.1 (high) · published 2026-11-05

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.

Weakness: CWE-120, CWE-125, CWE-787

Source: NVD CVE-2026-76077

References

• https://github.com/esa/asn1scc/commit/fe6ab763bc60d8a2def4104c15414809b45fffd9
• https://github.com/esa/asn1scc/releases/tag/4.7.0.1
• https://github.com/esa/asn1scc/security/advisories/GHSA-38q3-fg5h-wwf9

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