CVE-2026-64667pam_usb: Heap out-of-bounds read in pusb_get_tty_from_display_server cmdline scan
- 4.4MediumCVSS base score
- 0.16%Exploitation in 30 daysEPSS · top 95% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
pam_usb provides hardware authentication for Linux using removable media. Prior to version 0.9.3, src/local.c (pusb_get_tty_from_display_server) allocates a 4096-byte cmdline buffer, reads up to 4096 bytes from /proc//cmdline, then replaces every NUL separator with a space. When read(2) returns exactly 4096 bytes for any process the function inspects, the buffer ends without a terminator and the subsequent strstr() calls scan past the allocation boundary. The function is invoked during normal PAM authentication when DISPLAY is set, so the read fires for every process at auth time. Consequences are bounded: strstr output is a Boolean substring match (limited info-disclosure surface) but a hostile heap layout can produce a SIGSEGV that terminates the host PAM process. This issue has been patched in version 0.9.3.
Timeline
ID reserved
By GitHub_M
- 4 months later
· 4 months later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium4.4 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L |
| NVDNVD · Deferred | 3.1 | Medium4.4 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L |
- EPSS (exploitation in 30 days)
- 0.16% · top 95% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.4.
Affected products
References
References5
- https://github.com/mcdope/pam_usb/security/advisories/GHSA-gc6f-5hpq-ghxh (opens in a new tab)x_refsource_CONFIRM
- https://github.com/mcdope/pam_usb/issues/411 (opens in a new tab)x_refsource_MISC
- https://github.com/mcdope/pam_usb/pull/426 (opens in a new tab)x_refsource_MISC
- https://github.com/mcdope/pam_usb/commit/d0a2e716241304cdb069adfaf54d2ede629d57fa (opens in a new tab)x_refsource_MISC
- https://github.com/mcdope/pam_usb/releases/tag/0.9.3 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-123132 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64667)Record last updated .