FA-26486 / HTTP ranges / Open access
Part media types cannot insert extra framing lines · case 01
Part media types cannot insert extra framing lines.
ROOT CAUSE
The multipart-header-injection decision uses return media_type.
THE FAILURE
The multipart-header-injection decision uses return media_type.
Unsuccessful approach: The partial repair uses return media_type.replace("\r\n", " "), which still violates the stated contract.
Case contract
Return media_type if it contains neither CR nor LF; otherwise return application/octet-stream. This local serializer does not accept folded fields.
Why this case matters
Range responses combine representation identity, conditional requests, framing, and partial-object state.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(media_type):
return media_type
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('multipart-header-injection fixture 0', solve("text/x\r\nX: "+str(N)), "application/octet-stream")
check('multipart-header-injection fixture 1', solve("text/x\nX: y"), "application/octet-stream")
check('multipart-header-injection fixture 2', solve("text/x\rX: y"), "application/octet-stream")
check('multipart-header-injection fixture 3', solve("text/plain"), "text/plain")
check('multipart-header-injection fixture 4', solve("application/x; n="+str(N)), "application/x; n="+str(N))
check('multipart-header-injection fixture 5', solve(""), "")
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| multipart-header-injection fixture 0 | text/x
X: 1 | application/octet-stream | Failed |
| multipart-header-injection fixture 1 | text/x
X: y | application/octet-stream | Failed |
| multipart-header-injection fixture 2 | text/x
X: y | application/octet-stream | Failed |
| multipart-header-injection fixture 3 | text/plain | text/plain | Passed |
| multipart-header-injection fixture 4 | application/x; n=1 | application/x; n=1 | Passed |
| multipart-header-injection fixture 5 | | | Passed |
SHA-256 / 54a965222f53c8cb4aa01ee95b8170e9fd9dc94f4a3208b257679007c454f112
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(media_type):
return media_type.replace("\r\n", " ")
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('multipart-header-injection fixture 0', solve("text/x\r\nX: "+str(N)), "application/octet-stream")
check('multipart-header-injection fixture 1', solve("text/x\nX: y"), "application/octet-stream")
check('multipart-header-injection fixture 2', solve("text/x\rX: y"), "application/octet-stream")
check('multipart-header-injection fixture 3', solve("text/plain"), "text/plain")
check('multipart-header-injection fixture 4', solve("application/x; n="+str(N)), "application/x; n="+str(N))
check('multipart-header-injection fixture 5', solve(""), "")
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| multipart-header-injection fixture 0 | text/x X: 1 | application/octet-stream | Failed |
| multipart-header-injection fixture 1 | text/x
X: y | application/octet-stream | Failed |
| multipart-header-injection fixture 2 | text/x
X: y | application/octet-stream | Failed |
| multipart-header-injection fixture 3 | text/plain | text/plain | Passed |
| multipart-header-injection fixture 4 | application/x; n=1 | application/x; n=1 | Passed |
| multipart-header-injection fixture 5 | | | Passed |
SHA-256 / 73fa7eae4ad8e843bad2391e1b8f91cb5425d627929f5f99b0caa1ed34faeb4b
HELD IN THE MEMBER ARCHIVE
The verified repair and its recorded checks are member-only.
This mechanism has 6 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.
Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.
Member access is invitation-based. Sign in with your invited account to inspect the repair.
Sign in to the archive ↗Verification & scope
Deterministic simplified range service, with stipulated local policies and already parsed trusted inputs; not a complete HTTP implementation. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.
Observations recorded using Python 3.12.14 at 2026-09-29T14:41:16.395865+00:00.
Case digest / 20420d9af5b8c4685782a98b8fcaec1691cf20f9d196dc6e506a3bc6307a9e12