Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-76077— ASN1SCC: Stack buffer overflow and out-of-bounds read in XER tokenizer NT()

Quick assessment

Affected
esa asn1scc
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

ASN1SCC 是一款面向嵌入式系统的开源 ASN.1 编译器。在版本 4.7.0.1 之前，位于 文件中的 XER 词法分析器函数 （该函数会被所有 XER 解码路径调用）存在安全缺陷：它会将标签（tag）字符无长度限制地复制到固定大小的 缓冲区中，并且在读取输入字节和前瞻（lookahead）字节时未检查缓冲区计数。攻击者可构造包含超长标签的恶意 XER 消息，从而覆盖词法分析器的栈帧；而截断的标签、未终止的处理指令（processing-instruction）或注释序列则可能导致读取超出输入范围，引发 CP

CVSS 8.1 · High

Affected Version Matrix 1

VendorProduct Version RangeStatus
esa asn1scc < 4.7.0.1 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-76077

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
ASN1SCC: Stack buffer overflow and out-of-bounds read in XER tokenizer NT()
Source: CVE Program / CVE List V5
Vulnerability Description
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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
未进行输入大小检查的缓冲区拷贝(传统缓冲区溢出)
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
esa asn1scc < 4.7.0.1 -

II. Public POCs for CVE-2026-76077

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-76077

请登录查看更多情报信息。

Other References for CVE-2026-76077 (3)

Same Patch Batch · esa · 2026-11-05 · 3 CVEs total

CVE-2026-75614 8.1 HIGH ASN1SCC: Out-of-bounds write in BitStream_DecodeConstraintWholeNumber (uPER/ACN)
CVE-2026-75615 5.3 MEDIUM ASN1SCC: Out-of-bounds read via unvalidated character index in ASN.1 string decoders

IV. Related Vulnerabilities

Same product: asn1scc
Same vendor: esa
Same weakness: CWE-120