CVE-2026-76077
ASN1SCC: Stack buffer overflow and out-of-bounds read in XER tokenizer NT()
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| asn1scc esa |
< 4.7.0.1 (affected) | CNA: GitHub_M |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 8.1 high |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H | CNA: GitHub_M |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/esa/asn1scc/security/advisories/GHSA-38q3-fg5h-wwf9CNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/esa/asn1scc/commit/fe6ab763bc60d8a2def4104c15414809b45fffd9CNA: GitHub_M · x_refsource_MISC
- https://github.com/esa/asn1scc/releases/tag/4.7.0.1CNA: GitHub_M · x_refsource_MISC
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