CVE-2026-126049

Description

Gwenhywfar 5.14.2 contains a heap use-after-free vulnerability in GWEN_TLV_Buffer_To_DB() in src/parser/tlv.c, which frees a nested record's GWEN_DB node when parsing of its contents fails but continues processing and adds the freed node to the parent instead of returning. Attackers can supply a constructed BER-TLV record with unparseable contents, such as via a malicious chip card read by libchipcard, to corrupt heap memory.

References

• https://github.com/aqbanking/gwenhywfar/blob/f5c3f9dc56aa20cab85fd149885474239cf68632/src/parser/tlv.c#L651-L672
• https://github.com/aqbanking/gwenhywfar/commit/828b34135dfa33fc347a2929caa2f079ffb00738
• https://github.com/aqbanking/gwenhywfar/commit/dc8b80945e877f5bdf2d2ae1b50c928c15e990b0
• https://www.aquamaniac.de/rdm/projects/gwenhywfar/files
• https://www.vulncheck.com/advisories/gwenhywfar-5.14.2-use-after-free-via-gwen-tlv-buffer-to-db-nested-ber-tlv-parsing