CVE-2020-24240

GNU Bison before 3.7.1 has a use-after-free in _obstack_free in lib/obstack.c (called from gram_lex) when a '\0' byte is encountered. NOTE: there is a risk only if Bison is used with untrusted input, and the observed bug happens to cause unsafe behavior with a specific compiler/architecture. The bug report was intended to show that a crash may occur in Bison itself, not that a crash may occur in code that is generated by Bison.

• CWE-416

• https://github.com/akimd/bison/commit/be95a4fe2951374676efc9454ffee8638faaf68dPatch, Third Party Advisory
• https://github.com/akimd/bison/compare/v3.7...v3.7.1Third Party Advisory
• https://lists.gnu.org/r/bug-bison/2020-07/msg00051.htmlMailing List, Vendor Advisory
• https://github.com/akimd/bison/commit/be95a4fe2951374676efc9454ffee8638faaf68dPatch, Third Party Advisory
• https://github.com/akimd/bison/compare/v3.7...v3.7.1Third Party Advisory
• https://lists.gnu.org/r/bug-bison/2020-07/msg00051.htmlMailing List, Vendor Advisory

Published

Aug 25, 2020

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2020-24220ShopXO v1.8.1 has a command execution vulnerability. Attacke…8.8
• CVE-2020-24221An issue was discovered in GetByte function in miniupnp ngif…5.5
• CVE-2020-24222Buffer Overflow vulnerability in jfif_decode() function in r…7.8
• CVE-2020-24223Mara CMS 7.5 allows cross-site scripting (XSS) in contact.ph…6.1
• CVE-2020-24227Playground Sessions v2.5.582 (and earlier) for Windows, stor…7.5
• CVE-2020-24231Symmetric DS <3.12.0 uses mx4j to provide access to JMX over…9.8
• CVE-2020-24241In Netwide Assembler (NASM) 2.15rc10, there is heap use-afte…5.5
• CVE-2020-24242In Netwide Assembler (NASM) 2.15rc10, SEGV can be triggered …5.5
• CVE-2020-24246Peplink Balance before 8.1.0rc1 allows an unauthenticated at…7.5
• CVE-2020-24263Portainer 1.24.1 and earlier is affected by an insecure perm…8.8
• CVE-2020-24264Portainer 1.24.1 and earlier is affected by incorrect access…9.8
• CVE-2020-24265An issue was discovered in tcpreplay tcpprep v4.3.3. There i…7.5