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
Source GCVE Database
Not known to be exploited · CVSS 5.1 Medium : upgrade to 5.14.3 when convenient.
Data as of 10 Nov 2026, 19:05 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 5.1 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 4.6 |
- Patch
- Available – fixed in 5.14.3
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade Gwenhywfar to 5.14.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Martin PreussGwenhywfar | Affected
| Fixed in
|
GitHubGwenhywfarpkg:github/GwenhywfarOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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
- nvd.nist.gov/vuln/detail/CVE-2026-126049 (opens in a new tab)
- github.com/aqbanking/gwenhywfar/commit/828b34135dfa33fc347a2929caa2f079ffb00738 (opens in a new tab)
- github.com/aqbanking/gwenhywfar/commit/dc8b80945e877f5bdf2d2ae1b50c928c15e990b0 (opens in a new tab)
- github.com/aqbanking/gwenhywfar/blob/f5c3f9dc56aa20cab85fd149885474239cf68632/src/parser/tlv.c (opens in a new tab)
- aquamaniac.de/rdm/projects/gwenhywfar/files (opens in a new tab)
- vulncheck.com/advisories/gwenhywfar-5.14.2-use-after-free-via-gwen-tlv-buffer-to-db-nested-ber-tlv-parsing (opens in a new tab)