sqlmapproject/sqlmap · error · H2CompressionError

dynamic table size update is not at block start

Error message

dynamic table size update is not at block start

What it means

Error "dynamic table size update is not at block start" thrown in sqlmapproject/sqlmap.

Source

Thrown at lib/request/http2.py:495

            first = data[pos]
            if first & 0x80:
                saw_header = True
                index, pos = decode_integer(data, pos, 7)
                name, value = self._get(index)
                headers.append((name, value))
            elif first & 0x40:
                saw_header = True
                index, pos = decode_integer(data, pos, 6)
                if index:
                    name = self._get(index)[0]
                else:
                    name, pos = decode_string(data, pos)
                value, pos = decode_string(data, pos)
                self._add(name, value)
                headers.append((name, value))
            elif first & 0x20:
                if saw_header:
                    raise H2CompressionError("dynamic table size update is not at block start")
                new_size, pos = decode_integer(data, pos, 5)
                if new_size > self.max_allowed_size:
                    raise H2CompressionError("dynamic table size exceeds advertised maximum")
                self.max_size = new_size
                self._evict()
                continue
            else:
                saw_header = True
                index, pos = decode_integer(data, pos, 4)
                if index:
                    name = self._get(index)[0]
                else:
                    name, pos = decode_string(data, pos)
                value, pos = decode_string(data, pos)
                headers.append((name, value))

            name, value = headers[-1]
            list_size += self._entry_size(name, value)

View on GitHub (pinned to 0a35b20e39)

When it happens

Trigger: Thrown at lib/request/http2.py:495 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of sqlmapproject/sqlmap@0a35b20e39 (2026-08-26). Data as JSON: /api/errors/30471fa38eac3ab3. Report an issue: GitHub.