Gwenhywfar 4.99.8beta before 5.14.2 contains a stack-based buffer overflow in GWEN_TLV_Buffer_To_DB() in src/parser/tlv.c when decoding BER-TLV tags into a fixed 128-byte buffer
Source GCVE Database
Not known to be exploited · CVSS 5.1 Medium : upgrade to 5.14.2 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 5.14.2
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 5.14.2.
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 4.99.8beta before 5.14.2 contains a stack-based buffer overflow in GWEN_TLV_Buffer_To_DB() in src/parser/tlv.c when decoding BER-TLV tags into a fixed 128-byte buffer. Attackers can supply a record with about 127 or more tag continuation bytes or a truncated multi-byte tag, such as via a malicious chip card's EF_SSD file read by libchipcard's ZKA driver, to crash the application.
References
- nvd.nist.gov/vuln/detail/CVE-2026-126048 (opens in a new tab)
- github.com/aqbanking/gwenhywfar/commit/6b50388e6b4a96f02d3d56e1d7747405fa881f39 (opens in a new tab)
- github.com/aqbanking/gwenhywfar/commit/ed8e2f8cdc27fd5c1b629cf9c1f6b93b2e009757 (opens in a new tab)
- github.com/aqbanking/gwenhywfar/blob/424949d0c6e61028eaccd6e46e4c0c41931c2b2f/src/parser/tlv.c (opens in a new tab)
- aquamaniac.de/rdm/projects/gwenhywfar/files (opens in a new tab)
- vulncheck.com/advisories/gwenhywfar-4.99-8beta-before-5.14.2-stack-buffer-overflow-via-gwen-tlv-buffer-to-db (opens in a new tab)