Quick answers
- Is CVE-2026-76077 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-76077 being exploited in the wild.
- How severe is CVE-2026-76077?
- High severity, with a CVSS score of 8.1, published 5 November 2026.
- Which products and versions are affected?
- ESA ASN1SCC prior to 4.7.0.1.
- Is there a fix for CVE-2026-76077?
- Yes: fixed in 4.7.0.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-76077 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-76077?
- Check whether you run ESA ASN1SCC at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 4.7.0.1
Technical details
The XER tokenizer in asn1crt_encoding_xer.c uses a fixed 100-character buffer for tag values without bounds checking, and fails to validate input length before reading lookahead bytes. An overlong tag can overflow the stack buffer; truncated tags or unterminated sequences can read past input bounds. An attacker can craft a malicious XER message over the network (or via any input path to the decoder) to trigger memory corruption, disclosure, or crash.
Affected products
- ESA ASN1SCC prior to 4.7.0.1
Timeline
- 2026-11-05: disclosed