CVE-2025-66038: low-severity vulnerability in OpenSC
OpenSC: `sc_compacttlv_find_tag` can return out-of-bounds pointers
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
8Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 3.9epss 0.3%
OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, sc_compacttlv_find_tag searches a compact-TLV buffer for a given tag. In compact-TLV, a single byte encodes the tag (high nibble) and value length (low nibble). With a 1-byte buffer {0x0A}, the encoded element claims tag=0 and length=10 but no value bytes follow. Calling sc_compacttlv_find_tag with search tag 0x00 returns a pointer equal to buf+1 and outlen=10 without verifying that the claimed value length fits within the remaining buffer. In cases where the sc_compacttlv_find_tag is provided untrusted data (such as being read from cards/files), attackers may be able to influence it to return out-of-bounds pointers leading to downstream memory corruption when subsequent code tries to dereference the pointer. This issue has been patched in version 0.27.0.
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Affected products
OpenSC · OpenSCRelated CVEs — OpenSC
In the same product, most dangerous first.
CVE-2026-40510LOWOpenSC < 0.27.0-rc1 Stack Buffer Overflow via piv_process_history() in card-piv.cEPSS 0.3%CVE-2025-13763MEDIUMLibopensc: opensc: multiple uses of uninitialized variableEPSS 0.3%CVE-2025-66037LOWOpenSC: Out of Bounds vulnerabilityEPSS 0.3%CVE-2026-40528LOWOpenSC < 0.27.0 Buffer Overrun in do_key_value() via profile.cEPSS 0.2%CVE-2025-66215LOWOpenSC: Stack-buffer-overflow WRITE in card-oberthurEPSS 0.2%CVE-2025-49010LOWOpenSC: Stack-buffer-overflow WRITE in GET RESPONSEEPSS 0.1%