`abcd guard` allows a blocker written as the command string of `trap`, and bash runs it, an EXIT trap needing no further command.

abcd guard allows a blocker written as the command string of trap, and bash runs it, an EXIT trap needing no further command.

Private security advisory GHSA-f789-v342-57jr (draft, severity high). Full text, evidence and reproduction: the security-drain-2026-10-09 run directory in the main checkout's local tier. This record stays uncommitted until its fix lands; the fix commit adds it directly to resolved/.

Evidence (lines at main 7549ca2d5): evalPayload joins eval's operands and the guard re-reads that string, which is why eval -- 'git push --force origin main' is a block (internal/core/guard/payload.go:1578). Nothing walks the command operand of trap. The hook maps an allow to exit 0 and only a block to exit 2 (internal/surface/cli/guard.go:455-470).

Reproduction: Defaults().Check returns allow for trap 'git push --force origin main' EXIT, the same with ; true appended, trap -- '...' EXIT; true, trap '...' 0; true and trap '...' DEBUG; true. On /bin/bash 3.2.57, /bin/bash -c "trap 'touch $MARK' EXIT" creates the mark; the DEBUG form runs when a later command is present. The same text under eval is block / git-push-force.