CVE-2020-37239

libbabl 0.1.62 contains a broken double free detection vulnerability that allows attackers to bypass memory safety checks by exploiting signature overwriting in freed chunks. Attackers can call babl_free() twice on the same pointer without triggering detection, as libc's malloc metadata overwrites babl's signature field upon freeing, enabling potential memory corruption and code execution.

CVSS v4.0

9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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

CVSS v3.1

9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.46% chance of exploitation in the next 30 days, 38th percentile

Published

2026-05-16

Updated

2026-05-18

Proof-of-concept exploits (1)

• https://www.exploit-db.com/exploits/49259

References

• CVE Record
• NVD entry

Related

• CVE-2020-37238
• CVE-2020-37240
• CVE-2020-37237
• CVE-2020-37241
• CVE-2020-37236
• CVE-2020-37242