CVE-2026-100290 (GCVE-0-2026-100290)

Vulnerability from cvelistv5 – Published: 2026-11-11 15:56 – Updated: 2026-11-11 15:56
VLAI
Title
Double free after allocation failure in regcomp and regexec
Summary
The regcomp and regexec functions in the GNU C Library version 2.3 to version 2.44 may read freed memory and free the same heap block twice when a memory allocation fails while a regular expression is compiled or matched. The re_dfa_add_node (the NFA node table) and build_range_exp (bracket ranges) grow several arrays with consecutive realloc calls and store the new pointers only after all of them succeed. When a later call fails, the pattern buffer keeps pointers to blocks that were already freed, and the error cleanup frees them again. In regexec, the back-reference cache (match_ctx_add_entry) frees its array when a realloc fails but keeps the pointer, which is freed again on the error path. An attacker does not need to supply a crafted regular expression: patterns large enough to grow these arrays are common. The failure has to hit a specific allocation, though, so the issue can only be reached when the system is already under memory pressure. An attacker who supplies the pattern or the subject string has little control over which allocation fails, so the expected impact is a crash of the process. This issue affects all architectures and ABIs supported by the GNU C Library.
Severity
3.7 (Low)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE
Assigner
glibc CNA under the redhat root
CNA scorecard B 79/100 over 16 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
The GNU C Library glibc Affected: 2.3 , ≤ 2.44 (custom)
guessed Create a notification for this product.
Date Public
2026-09-08 05:00
Credits
Tristan
Show details on NVD website
To clipboard 

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