CVE-2026-128238
Scapy before 2.8.0 Uncontrolled Recursion DoS via BER SEQUENCE Decoder
Scapy before 2.8.0 contains an uncontrolled recursion vulnerability in the BER/ASN.1 decoder in scapy/asn1/ber.py that allows unauthenticated remote attackers to crash parsing applications. Attackers can send a single 833-byte packet with 250 nested ASN.1 SEQUENCE structures to trigger an unhandled RecursionError, terminating TLS, SNMP, X.509, or LDAP parsers even with safe=True.
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 |
|---|---|---|
| scapy secdev scapy
pypi |
≥ 0; < 2.8.0 (affected, semver) 2.8.0 (unaffected, semver) Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 6.9 medium |
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 5.3 medium |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L | CNA: VulnCheck |
| 4.0 / 6.9 medium |
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD: [email protected] |
| 3.1 / 5.3 medium |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/secdev/scapy/security/advisories/GHSA-456h-w4v7-hvprCNA: VulnCheck · vendor-advisory
- https://www.vulncheck.com/advisories/scapy-before-2.8.0-uncontrolled-recursion-dos-via-ber-sequence-decoderCNA: VulnCheck · third-party-advisory
- https://github.com/secdev/scapy/security/advisories/GHSA-456h-w4v7-hvpr[email protected]
- https://www.vulncheck.com/advisories/scapy-before-2.8.0-uncontrolled-recursion-dos-via-ber-sequence-decoder[email protected]
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